If "now" means November, I say "now".
Think about it, since the MT2W engine is an evlolution of the completely new RTW engine, it shouldn't be quite as buggy as RTW was on release (which I didn't think was too bad anyway). Balancing is another issue entirely. I expect it to be rather poor. As far as I'm concerned, the features are the most important, as they're unlikely to change after release. Balancing issues can always be addressed.
Bookmarks