My vote on this is that SEGA needs to play the wait and see card. Either with taking Total War into the MMO territory (because until Empire, most of the install base hadn't been all that internet or micro-transaction savvy) or going the 3D route with any of their titles / franchises. Let's get the games right first is the best move they can make.
With Total War, I'd like to see more of a community toolkit come first with Facebook implementation, a more consolidated forum that's not spread between third and first party sites, etc. Once that's been established and the game franchises are all linked again, moving into an MMO environment would be easier and far more viable.
As for going into 3D territory, until SEGA is solid on making quality games (and this year's line has been very solid and fun so far) consistently, it's not something they should try investing money in. Hopefully, to that end, they'll follow their own advise...