Well.......... that's not too harsh for Half Life2, but for Doom3 those numbers are probably going to skyrocket. I think everyones going to be prepared though.
Half Life 2= Nothing lower then this...
*700mhz Processor
*128 mb of RAM
*64 mb Video Card
**Note** This will likely change as the release date approachs but this was a quote from valve awhile ago. They want to make sure it will run on older PC's.
Doom 3=Pretty steep!
*Video card with at least 128MB RAM and Pixel Shader 1.1
*256 Ram
*2.5GHz CPU
**Note** These requirments were released from John Carmack from ID software in an interview. Again..may change as the release date approaches.
Those requirements were in fact NOT actually released by John Carmack.
I remember that was on Doomworld.com a while back, but they later confirmed that the interview, taken from a magazine article, was in fact false, and that ID had even confirmed that the article was false.
As for HL2 and Doom 3 specs, I would say that they are both going to require about the same, considering both are packing about the same graphics, just that each is set in a different atmosphere.
look at my siggy....$1000...a little more including some extras but it can still play Doom 3...and check ebay i heard a Falcon Northwest custom built was bought for only $500!!!