Regarding Yapp, from what I've heard he took care of his opposite against Castres and had a pretty good game. His best asset is the ability to cover loosehead and tighthead. Stodds has looked rather dangerous attacking, lets see him step it up with the tackles.
Prepare to be prooven wrong. Paul James will edge Cole scrum time and Mitchell will hold it steady against Sheridan. Scrums are very rarely a deciding factor in an international match unless it's against the Aussies, especially considering most refs don't know what the fu*k is going on. Wales' second and back-row have the edge imho. Bradley and Alun-Wyn have formed a great partnership recently. In the backrow, Warburton has been prooving himself against the best over the past year and come out favourably in every test, whilst Lydiate will tackle everything that moves. Powell is there in order to provide some go-forward ball, and if he can translate any of his club form into this game, he will be able to provide something Wales has been missing recently. Great balance in the backrow imo.
The backs look decent imo. Whilst I'd prefer Hook to be closer to the action, he should do a job at 15. Defense of the back three may be a slight concern, we'll have to wait and see. Defense in midfield will be rock solid though! Decent looking bench for Wales aswell if you put your finger over Yapps name!
I'm going for a Welsh win by a few points, because I think with Lydiate and Warburton we'll win the breakdown providing quick ball to our backs.