Today PlayStationUniversity.com (linked above) reports that a Sony Computer Entertainment Europe http://research.scee.net/files/presentations/acgirussia/Hardware_Overview_ACGI_09.pdf [PDF] has made its way to the Internet from the All-Russian Conference on Game Industry (ACGi) 2009.
It reveals, among other interesting things, that the PS3's OS footprint has again been slashed down to 50MB in the latest PS3 Firmware revision.
As mentioned previously, back in PS3 Firmware 1.80 the PS3's memory footprint was reduced to 74MB.
The document also outlines PlayStation Development Resources, Architecture of the PlayStation 3, Case Studies for both PSP / PS3 and Advanced Programming... definitely a good read at 86 slides long!
More PlayStation 3 News...