I hope PS3 steam will eventually do game updating/DLC/Maps for portal 2 and future valve games too.
Thanks for all the very interesting feedback, I agree with the people who believe it would take a real leap of faith by Ninty to let Valve do the online network, but thats the impression Iwata seems to be giving in his interview - that because of the failure of Ninty inhouse team they are ready to choose a dance partner - and valve is the most attractive one available.
Valve doesn't need to use Steam it's self, instead they could use some of the framework of steam ( which they can intergrate with there main steam system for there own games) and create a ninty "stream" network with talior made aspects allowing for 3DS connectivity etc.