I've had the Wii for about 3 weeks now, and here are my first impressions:
If you want to try to interest a non-gamer in videogames, then then Wii is your best bet. I brought it to Russ' family Xmas day get-together, and more than once people who had not really been into gaming before said "Where can I get one?!?!" by the end of the day. They all had a blast with Wii Sports (especially tennis and bowling), and got a kick out of Rayman Raving Rabbids too.
The Wii's menus and controls are consistently easy to use, and have a clean, bright, albeit slightly boring, design. The newly enabled weather Globe is a surprise favorite of mine. It's fun, elegant, and a relaxing way to spend a few minutes every couple of days to see what the weather is like around the world.
The Wii's graphics on my 1080p LCD TV looked quite pixellated, even using the component cable. After getting used to seeing my PCs graphics on my TV (a Westinghouse LVM-42W2 that lets me run my PC through it at 1920 x 1080 resolution...EQ2 looks GREAT!) as well as my 360's, the Wii's graphics are, to put it kindly, underwhelming. However, moving it to our older TV (a Toshiba 1080i DLP) improved the look. I know it's common to say "It's not about the graphics, it's about the gameplay", but I guess I've been spoiled beyond recovery by newer hardware, because I'm finding I need a certain level of graphics to truly enjoy a game. Gameplay is still critical, but when you can have both, why settle for just the gameplay?
I'm sure I'll still have lots of fun playing the Wii, but I suspect I'll mostly play it when I'm with other people in person, especially if they're not avid gamers. When I want to sit down for an extended session of solo or online gaming, it will be on my PC, PS3, or 360. With all these latest-generation options, I don't imagine I'll use the Wii as much as the others.