This is not the official, but a user-compiled Starcraft II tech tree. It's partially imcomplete and obviously is subject to change. Here goes:
Protoss
Terran
Zerg
We will be discussing the new Tech-tree this weekend in another addition of our "In-depth Look at Starcraft II", so stay tuned. Our thanx to "Enron" for the tip.
Links
SC.IncGamers.com - Source
Starcraft2.net.pl - Original Designers