No, none of the 40GB versions have backward compatibility. The 60GB version has hardware BC, and the old 80GB version has software BC (which supports less games than hardware BC). The 80GB version that is now being released has no BC. It's very frustrating for people contemplating a purchase in the near future (like myself) who want BC.
I'm cranky today, so you get my English lesson, Teggy.
Less is used when you're talking about an unquantifiable amount. For example, "Less Filling."
Fewer is used when the quantity can be defined with a number. For example, "Fewer calories" or "Fewer games."
There is a site to check compatibility (http://www.us.playstation.com/Support/CompatibleStatus
), but, yeah, you're out of luck with the 40GB.