The official requirements for Lara Croft’s latest escapade Tomb Raider Underworld has not been out yet.
Game Information
Proposed Release Date: 21 November 2008
Publisher: Eidos Interactive
Developer: Crystal Dynamics
Genre: Action Adventure
ESRB Rating: RP
Game Platform: PC, Xbox 360, Wii, PS2, PS3, DS
Here is the ‘speculated min sys req’ that I got over at a forum (tombraiderforums.com)..
Minimum System Requirements:
Ati radeon [...]

Tomb Raider: Underworld, also known as Tomb Raider 8, is the eighth game in the Tomb Raider series and the third game in the series to be developed by Crystal Dynamics. It will resume the adventure from where Tomb Raider: Legend left off and address elements of the plot left unexplained in Legend and [...]

Spore is a simulation game created by Will Wright that allows players to control various life forms from the cellular to the galactic level. Publisher: EA Games and Developed by Maxis

Minimum System Requirements SPORE (PC Game)
OS : Windows XP  [For Vista, see reqs. below]
Processor: Pentium 4 @ 2 GHz or Equivalent AMD Athlon
Memory: 512 MB+
Hard [...]

 
New Features :

A living and breathing world – virtual monsters and stalkers migrate around the Zone, similarly to the player they are preoccupied with day-to-day things – feeding, fighting, looking for prey, trading, sleeping, taking rest
Freedom of movement around the storyline, limited only by the player’s will and abilities
The world of post-Soviet environment
Authentic objectives of [...]

First Encounter Assault Recon (FEAR) Minimum System Requirements
· Windows® XP or 2000 with latest service pack installed
· DirectX® 9.0c (April Edition) (included)
· Pentium® 4 1.7 GHz or equivalent processor
· 512 MB of RAM
· 64 MB GeForce™ 4 Ti or ATI® Radeon® 9600 or equivalent with hardware T&L and pixel shader support
· 5.0 GB free [...]