The release date for DCUO has been announced as 11th January 2011 and to go along with tht we have the official DC Universe Online system requirements

DC UNIVERSE ONLINE MINIMUM SYSTEM SPECIFICATIONS:
Windows XP 32 bit
P4 3.0 GHz or AMD equivalent
NVIDIA 7800+ or ATI 1950+ Video Card
1 GB of RAM
30 GB of Free Hard Drive Space
Broadband internet connection

DC UNIVERSE ONLINE RECOMMENDED SYSTEM SPECIFICATIONS:
Windows XP/Vista/Windows 7
3.0 GHZ CPU Dual Core Processor
2 GB RAM
NVIDIA 8800GTX+ or ATI 3800 series+ Video Card
30 GB of Free Hard Drive Space
Broadband internet connection