Some other ideas that crossed my mind.
In the event of a create/edit players option (which I think is a must have for that game as we don't know when the next is gonna come after that), It would be nice that like other sports games (NHL09/10 from the top of my head), Save files are not one big option file.
Iit would be nice to have the Roster save file separated on PS3/360 in order to have the community updating/modify the rosters and be able to share them (another thing would be to make sure than an alien roster file doesn't block out trophies on PS3).
Alternate position for players, especially in Be A Pro (if such a mode is in, I'm sure it's been discussed on this thread before). A lot a rugby players can play at different positions.
I say that because for example in NHL09/10 there's no alternate positions, so if you're a center contracted by the penguins, you'll never play on crosby's line because if you get promoted to first line, you'll boot him to second, which is stupid and unrealistic.
Imagine booting Carter out of the starting 15 playing for the crusaders... So a player could have one preferred position and one or two alternate for the coach to choose from, or you could have to coach AI determine what other position the player could be good at based off his stats.
Online play must have been discussed, as it's a must have for a sport game. Now that's the geek in me speaking, but I was thinking about being a little more innovative with online player ranking than just something based of win & losses.
Something inspired by the IRB ranking for nations could be pretty fun (but on a greater points scale). It wouldn't favor high ranked players playing low ranked players because there wouldn't be any point exchange, but would favor the bolds trying to overtake higher ranked players by trying to win against skilled players.
Another is: this time around, it would be nice to try to have ALL the rules in the IRB rulebook be integrated. I seem to remember for example in Rugby 08, when a kick-off/restart kick did go directly into touch, there was an automatic scrum at midfield.
While I can agree that because 99.9% (I would say 100% but I'll stay on the safe side) of the time, the team will choose the scrum, we could let that be an automatic.
But still, in the rulebook there's a choice: have the ball kicked-off again, scrum at midfield and accepting the kick (lineout on the halfway line). I think this is an important point.
If I feel that my scrum is suffering and that I'm more comfortable with my lineout, I would choose the lineout, given a chance to have a choice.
Another fine option would be to be able to edit rules: choice to activate them or not, choice of the different options an offence gives (though I suppose this would be harder to implement)