those 6 months you're talking about, are they based on a specific game or just a wild guess?
Wild guess and a silent hope that the mainstream industry will come up with something cool (multiplayer wise) during the next 6 months. ;-)
Don't get me wrong - I am looking forward to many games but not ones that would fulfill our requirements... I must say I was shocked myself to see that there are e.g. next to no multiplayer shooters to anticipate since that's also what I'm usually reviewing. I guess it will be a tough year financially. ^^
We can look forward to stuff like StarCraft 2, Battlefield Heroes or Diablo III which will surely spawn a vivid community BUT they don't require any hosting on our side.
Perhaps Call of Duty: World at War? But it's slated for a November release... Other than that I only see titles that won't have multiplayer, no dedicated servers or will plainly suck. ;-)
Since SaintK is planning to go to the Leipzig GC he will probably come back with more news - some titles are announced only on big conventions or only several months before release (just like movies). There's still hope that something unexpected will pop up but currently we have no alternatives to TF2, I guess, if we stick to the criteria you mentioned.