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.
SCEA's Patrick Seybold recently confirmed the change to Joystiq. "Since the launch of the PS3, we have been continuously making efforts to reinforce our support system to game developers, allowing them to express their creativity freely on the PS3. As part of this support for game development, the size of the PS3 OS memory footprint has been reduced through network update for the game developers."
While 70MB of additional memory is not insignificant, don't expect drastic changes to future PS3 games. A PS3 developer told us that "any bit of RAM helps. Generally it probably won't change design, but might allow extra effects resolution or dynamic lights or something. Probably more beneficial from the systems and art side then from design/gameplay." In tandem with increasingly efficient code, the added RAM will undoubtedly make for even better looking games. Certainly, that's not something we'd complain about.