I really think that if Nintendo "fixed" their online situation to more closely match the 360, and provided 1 level demos for the VC content, they would garner a lot more interest for the console from a wider range of users.
My Wii gets used mainly by my kids, but I disagree that it's a "kiddie machine". The VC attracts older gamers, and if we just let a bit more time pass, there will, I believe, be more adult oriented games available for the system.
It's a weird machine, with weird controls, and will therefor take a bit more time to "find itself", just like the DS. Also, even though I'm glad it plays games from Nintendo's past, that backwards compatibility is a double edged sword, it tends to water down a system, and focus is harder to achieve. So, give it time, nay-sayers, it will come into it's own one day, and it'll be great.
All that being said (or out-gassed perhaps,) I voted 360 because, for right now anyway, I play it more.