I've had my Wii for a few months now and I love it. It's a great gaming console but it's other features are even better.
The reason the Wii is so popular is it's pick up - put down playability. I can come home from work - play Wii tennis for 5-15 minutes and then cook dinner. This allows me to unwind from work/uni before I get to my household chores.
Typically gaming consoles have a rough inverse exponential learning curve - meaning that if you aren't (or haven't) willing to invest some time in learning how to play then you'll never be able to enjoy yourself. This isn't the case with the Wii - while some games are truly hard to master practically anybody can pick up the basics.
At the moment their aren't as many Wii games as I'd like - there is still a pretty sweet collection. (At my work we are renting about 40 titles at the moment and I've tried most if not all. *Hint look at my profile for where I work) The title I am really hanging for is Wii cricket, I just know if they ever make it it's going to go off like a packet of socks.
Even if you aren't really interested in gaming - this console still has something to offer. I've set it up so the wireless works with my Wii which allows me to use the browser. Through this browser I can watch YouTube videos and endless other junk through the Wii. I've also hooked up my computer to the TV and use the Wiimote to navigate through my computer when I am in bed. (Handy for late night browsing and checking stats - as well as watching any movies you've got on your PC on the bigger screen).
The wiimote is revolutionary - don't listen to what any of the naysayers say. Of course be careful of the wiimote flinging into your TV (it's happen - the cord sometimes breaks) but as long as you aren't over zealous - you should be A-Ok.
Two thumbs up - even though I haven't used it as much as first expected.