I don't believe that Nintendo can take the #1 spot. Even if they do, it would'nt matter to me all that much. What does matter to me is Nintendo sometime next-generation obtains the following:
a) Great 3rd party support similiar to that of Sony
b) The Revolution remote isn't a gimmick; rather, industry standard
c) Nintendo's own software kicks ass
I'll just talk about choice "c", for a second. I felt that while Nintendo had a good generation in general with GCN and their own software, I felt it paled in comparision to Nintendo's past. And this point has been driven over and over again, by myself and alot of posters in these boards. I hope Nintendo hasn't lost their creativity that we associated with them during the NES/SNES/N64 eras.
Anyway, I think the Revolution will match SNES levels of userbase. Yeah yeah, you all can laugh at me now.

But really, I honestly don't think it's THAT far fetched. SNES sold in the neighboorhood of 50-60 million, right? But this is me thinking that the Revolution control actually is something worthwhile to buying, consumers don't care THAT much whether the PS3 blows Revolution games graphics out of the water (this will ring true the entire generation), and that 3rd party and Nintendo make their due by making good games.