Yeah, the Wii's not doing so bad. I don't think it'll keep sales afloat as long as the PS2 did, but it's still Nintendo's best selling home console... ever.
I also personally think that both Nintendo's decision to continue doing pack-ins, basically ensuring each console sale is a first-party software sale as well, is keeping the price up. After all, the special edition Blue consoles last fall had no game and were at $99.
As for the $360, it's actually only now coming into its own, been topping monthly npd hardware sales, perhaps helped by momentum driven by kinect. I can see why MS wouldn't want to talk about the 720 at this year's E3 if true, it would dampen current profitable sales, and it isn't strictly necessary to do even if they want to launch the 720 in 2013. Let's not forget, this is the first time ever MS is starting to make some progress at earning back some of that money ($10 billion?) they poured into their XBox gaming division. I don't think I can blame them for wanting to keep enjoying that profitability before they commit once again to a major console investment.
With a 2013 launch, and Wii U defining features known in 2011, my wonder is how much MS copies, or even improves, Nintendo's feature set with the 720. On the one hand, this would help Nintendo because shared features might validate Nintendo and help porting between the two platforms. On the other hand, if third parties and third party gamers choose to treat their console support options as an "either/or" instead of an "and" choice, the 720 might have a clear advantage over Nintendo.