It's pretty obvious why we haven't heard any info about TF2, it's the same reason they never mentioned TF2 in the past. If they released any info on TF2 they'd be giving away info about HL2 multiplayer which is supposed to be something really fun and amazing that we've never seen before. Once HL2 is released I'm sure we'll be seeing plenty of info on TF2... unless they want to keep that a secret too... Too hard to tell what the hell Valve is going to do. It's one surprise after the next.
...Christmas in September.
...Christmas in September.