I am not too worried about gameplay; I think that valve is putting a lot of effort into that since the game is about fun mostly and I'm sure that they are looking into it. Also I just love how the art team put together those character styles, I think that they look amazing!
We can speculate about whether tf2 will be fun to play, will be suitable for clan-style and how it's gonna differ from ff but it'll just be speculating... we'll just have to wait..
And in the meanwhile I'm feeling pretty dumb for (only) recently buying hl2/episode one since that orange (not yellow though) box thingie would've been a much better choice (and I'm not even playing hl2 right now). Is there still gonna be a (cheaper 
) ep2/portal/tf2 package?