How much does a PS3 cost - wattage wise?

I wondered whether the 40GB PS3 at 399 euro's is a better deal than a 499 euro's 60GB PS3 with 2 controllers and 2 games. It seems like a no brainer, but it isn't when you start wondering about things like: did Sony upgrade components in the newer PS3 (do you get better technology)? Will future firmware upgrades work on both models? Will the fact the 60GB-model runs hotter mean it has a shorter life span? And what are the extra cost of the more power hungry 60GB model, that uses 200 Watt instead of the 135 Watt the new 40GB model consumes.

Accoording to this website, a 200 Watt appliance, used 2 hours 180 days a year, currently would cost 16 euro's, while a 135 Watt machine would cost 11 euro . But energy cost will rise? And should i also think about the environment. The 60GB-model does have backward compatibility. But the fact you get 2 nice games AND an extra controller for 100 euro's make me consider the 60GB model: the BC is a nice extra.

By the way: did you know Consoles Worldwide Use 16 Billion Kilowatt Hours per Year?!

(picture from DansDecals.com)