Confirmed: The new 80 gig PS3s have 65nm RSX chips.

[BKK2]

They actually already switched to 65nm RSX on later models of the 40Gb (CECHH).

Here's the different mobos up to CECHH (I haven't seen any pictures of new 80Gb mobo yet):

COK-001: CECHA (60Gb), CECHB (20Gb): 90nm CELL / 90nm RSX / GS+EE Chip



COK-002: CECHC (60Gb), CECHE (80Gb): 90nm CELL / 90nm RSX / GS chip



SEM-001: CECHG (40Gb): 65nm CELL / 90nm RSX



DIA-001: CECHH (40Gb): 65m, CELL / 65nm RSX



Size comparison, COK-001 Vs DIA-001:



There are several different new 80Gb model numbers planned (CECHJ, CECHK, CECHL. CECHM), so it seem that there are more mobo revisions to come. Maybe some of the later ones such as CECHM will have 45nm CELL.