You are wrong; it still uses the old 90nm chip (and not the 65nm one - note: 65nm and not 60nm). This has been confirmed by Sony:
Sony says: "The new 40GB model is still using 90nm technology"
CellRemember last Monday when German c't magazin put the rumor out that due to the much lower power consumption of the new 40GB PS3, the new model is running on 65nm technology, other than the former models which are all based on 90nm Cell and RSX chips.
It took Sony some time to officially deny this rumor, as the current model is still based on 90nm technology. The new 65nm based hardware is about to come out during the next month or so. Asked about the lower power consumption, Sony said that this is due to the usage of other more optimized chips.
So, the good news about this is, that there is obviously still a lot potential within the hardware in terms of reducing the power consumption even more and scaling the hardware down to a new level. Will be interesting to see when the first change in the consoles form factor will take place, similar to the PS2 slim version.