The EPG and subtitles are all that I feel 100% confident about at the moment; we've seen those through all the recent betas, without any serious issues or side-effects.
Until we have a final release, and see what else has been changed, I'm not going to say what else will make the final cut; for example, we had an early EPG fix before the December release, which didn't make it in.
All I will say is that work has been done in lots of areas; it's a question of seeing which things the testers reckon are ready for prime time, and which might benefit from more tweaking.
Nigel.