Initial impressions are that it is a lot better than I thought - very responsive and nice interface and so on.
But I have to say I wouldn't buy one. I personally think the novelty will wear off quite quickly and the limitations of the controls will mean that after a while, games will all start to feel kind of the same.
Also, and this may be because I'm in my early thirties, Wii Sports Boxing has just left me completely knackered. I really can't imagine coming in from a long day at work and thinking that playing that again would ever seem appealing.
So, to sum up my Wii view, great fun at parties and I imagine highly amusing when drinking in groups but not really a daily-play console for folks like me.
Bloody good exercise though, so I applaud Nintendo for bridging the gap between computer-game-culture and physical activity.
Off to collapse now. Night.