Could be. Then again, even the most official system specs are liable to have their goalposts moved a little this far out from release, so consider these unconfirmed ones more of a rough guide than a definite listing of all the new hardware you may or may not need later this year.
Minumum Requirements
GFX: GeForce 7/8 Series or Radeon 1000/2000 with 256 MB RAM
CPU: Pentium 4
RAM: 1 GB
Internet: ADSL 1 Mbit
Recommended Requirements
GFX: GeForce 8000 or Radeon 2000 series with 512 MB RAM
CPU: Core 2 Duo or Athlon X2.
RAM: 2 GB
Internet: ADSL 3 Mbit
These were obtained by Spanish mag Micromania, after a visit to Blizzard's offices. As such, I'm just going to class them as "official estimates", confirm my PC can run the recommended specs, then get on with my "waiting for Starcraft 2" candlelight vigil.
StarCraft 2 Minimum Requirements [Micromania, via Voodoo Extreme]