It's rare for a console to get a spec upgrade in the middle of its life. However, Sony has stealthily upgraded the PS3 over the past few months to unlock additional usable RAM for developers. Much like the PSP received a boost in clock speed, the latest firmware updates provide developers an additional 70MB of RAM to work with. The change was initially discovered by PlayStation University, noting the reduction in the system OS's memory footprint, from 120MB to 50MB. As the OS continues to slim down, developers are allowed access to even more usable system memory.
Source :
http://www.joystiq.com/2010/02/23/70mb-of-additional-ram-unlocked-for-ps3-developers/
Sounds pretty good. I don't think its going to mean that games will suddenly be 100x better but at least its something