It looks like Wales are within .02 of Ireland's ranking score after that thumping victory. If they beat France they'll almost certainly be a top 4 ranked side going into the RWC draw.
From all the fair remarks above, all I'd argue against is criticism of Wales for not blooding new talent (compared to Ireland). Yes, they could and maybe should have done that in November, but with ranking points at stake (and a possible group of death to avoid) I can see why Wales solely played to win and avoided any experimentation - it is only now they are guaranteed not to be in the third pot of seeds, but next week they will be playing to be a top seed, so again no experimentation even though the 6N is basically over for them. Plus Howley is auditioning for a big promotion at his work so is unlikely to move away from what he considers his most reliable lineup (it may even be that Gatland won't let him).
Wales are ageing a bit in the forwards, but don't have an abundance of alternatives. In the backs they aren't too old at all and Scott Williams has dislodged Roberts. Amos might well have muscled his way into the back 3 if he hadn't got crocked (his 20 min pre-injury cameo in November was arguably a highlight in a Welsh shirt). A back three of North, Amos & Liam Williams would be youthful, intelligent and creative, with the potential to be the best in the competition and put in a star turn at the RWC. There is no need for big experiments.
With a Lions tour and then November tests, there'll be plenty time for Wales to try out some new personnel before the next 6N. Two of their Pro12 sides are firing on all cylinders. My point being, cheer up Wales, your union is being run in a fairly competent manner.
Who would argue against Howley as Gatland's successor if Wales enter the next RWC as a top seed?
Imo you're giving Howley and Wales a little too much credit. They've looked poor for the majority of the last 3-4 years, with only the odd good performance. Those good performances show that we're fully capable, but for the majority the coaches fail to consistently get that level of performance from the side. If Wales go into the WC seeding's as one of the top 4, it probably highlights just how poor some of the competition are atm. SA in particular are nowhere near the standard they should be.
Before the match Howley reeled out the over-used expression "you don't become a bad team overnight", more apt at the moment would be "you don't become a top team overnight". We shouldn't get carried away after yesterdays result. We could have easily lost, whilst Ireland weren't at their best. Wales played pretty well overall, but imo still far from what they are capable of:
1 Rob Evans 7. Held the scrum well against the impressive Furlong. Put himself about, and carried strongly throughout. Showed some good hands at one point, sending a lovely long pass out to his backs (scary though!).
2 Ken Owens 8. Really impressive game from the Hooker. Nailed every lineout, whilst his workrate in defense and attack was excellent.
3 Tomas Francis 6.5. Solid enough, and got involved a little in the loose. Still not as mobile as I would like.
4 Jake Ball 6. Mostly played well, offering himself as a carrier and stole a lineout. Struggled to make too many yards, and also gave away at least one soft penalty at a maul. Far batter than v Scotland though.
5 AWJ 7. Industrious display as always. Decision making as captain was spot on this game, maybe showing that he's fully adjusted to the role. Stole a lineout to boot.
6 Sam Warburton 8. Another excellent display. Everywhere once again in both defense and as a carrier. Barnes gave nothing to either side at the ruck in terms of turnovers, so he couldn't shine there; but did slow ball down.
7 Justin Tipuric 7.5. Combined well with Warbs, and similarly showed up well in defense. His workrate is similarly impressive, although not as physical as Warbs (one big tackle stood out though, where he drove the Irish player back 5m). Didn't get a chance to shine in open field, but we know that's ready to unleash when he get's a chance, so it's great that he's still proving his worth despite this.
8 Ross Moriarty 7. Another good, if unspectacular performance. One moment stood-out where he was pushed into touch when Wales were pressing when Sexton was off the field. Hopefully he'll learn from that, but it's not a great thing to see from your no. 8.
9 Rhys Webb 8. Made a few mistakes, firing out a couple of too long and flat passes early on which almost got intercepted. However he was Wales most creative player, setting up North's first try, and generally finding space. Thought he had a great game, and Wales didn't look the same when he went off.
10 Dan Biggar 5. Some good defensive interventions, and covered well at fullback when required. Really struggled to influence the game offensively though! Also dropped a couple of high balls you'd expect him to take.
11 Liam Williams 7. Always makes ground, and hits above his weight. Along with the rest of his team-mates he struggled under the high ball.
12 Scott Williams 6.5. Solid throughout, and keeps showing nice touches. Can play much better though.
13 Jon Davies 7. Another good performance. it's making such a difference having him playing well. He's great defensively and makes metres with ball in hand.
14 George North 8. Great to see him back. Showed the kind of power and pace we know he all has. Great to see him making good decisions defensively, and making his tackles. One cross kick aside, he wasn't exposed prepositionally like he usually is. Unlucky not to secure a turnover at one stage in the second half where he appeared to be over the ball for a good few seconds. Solidity under the high ball was his only negative really.
15 Leigh Halfpenny 5.5. Not his best performance. Looked shaky under the high ball, and still isn't showing too much in attack. However he was rock solid in his tackling, and his place kicking was what you'd expect from him.
17 Scott Baldwin 5. Not convinced he should be there at all. Shaky in the lineout, where we went from slick to under pressure.
18 Nicky Smith 6. As always, he get's around in open play, and his quick feet help him make meters with ball in hand. Scrum started to struggle once the substitutes entered the fray.
19 Samson Lee 5. Still struggling really. Scrum was under pressure, and didn't notice him much in the loose.
20 Luke Charteris 7. Good cameo, stealing a lineout and showing up well in the tight.
21 Taulupe Faletau 7. Far better from him. Good linespeed to charge Sexton down for the score that took us clear.
22 Gareth Davies 5.5. Pressured well defensively, but he's a decent step-down from Webb. Box kicking also a worry.
23 Jamie Roberts 6.5. Did well when he came on to be fair. Not convinced having him on the bench, but he defended well when he came on, and took his try well.
I'd still like to see Howley make a few changes for France. Sam Davies should be given an opportunity to start, Liam should be given another go at fullback with one of Steff Evans of Giles coming onto the wing. I'd bring Faletau back in at 8, with Moriarty tasked with making a big impact off the bench.