Last week, we had the author of TDD for a Shopping Website LiveProject. Friday at 11am Ranch time, Steven Solomon will be hosting a live TDD session just for us. See for the agenda and registration link
As much as it does any other technology. Whether or not you should use HTML5 and CSS3 for the interface depends on how you want to distribute your app, what your target audience is and (if you use the web) what browsers they're using. I don't think whatever happens to be at the back end is a major factor in your decision.