This generation, it seems that it has become increasingly common to own more than one system. That said, what about next generation? Are all of you really excited about the prospect of owning two (very similar) systems if it costs $700? I know I'm not. And yes, I know they have their differences, but honestly, are they significant enough to warrant having both?
Then there is Nintendo, which promises a different experience at a much lower cost. So you've already got your HD system - what if your second console was actually something different? And what if going for that saved you as much as $200? Not to mention all of the games that you know will be great HD or not (Zelda, Metroid, SSB, etc.). And what about all of the downloads?
In addition, third party games should cost less to make for Revolution (they don't have to worry so much about optimization). So what if they made them cheaper? If a game was $10-$20 less on revolution, that would certainly be some incentive to get the revolution version. Surely you will want the HD versions of your favorite games, but what about games that you are less interested in (or games in which the graphics just don't matter or are not as good). Will it really be worth more money just to get the HD versions?
A lot still remains to be seen, and I think that quite a bit rides on their "revolutionary" features (more than I originally thought, anyway). But Nintendo could make itself a good 2nd console, and that is, IMO, a perfectly good place to be. After all, if half of the people who bought a console bought an X360, and the other half bought a PS3, but everyone chose the revolution as their 2nd console - it would turn out pretty well for nintendo. (and yes, I realize that this is an exaggeration/simplification, but you get the point)