I bought it about a month ago, and I think I'm one of the few people that got exactly what I'd expected.
I've lost about 9 pounds so far (well, not just with WiiFit - with a combo of WiiFit, an hour of cardio 3 nights a week, and eating a little healthier), and I have to say that it actually is a workout. I try to get in at least 30 minutes a day (usually closer to 45), and by the end, I'm always sweaty enough to need to shower.
I have to agree with Fisky in that some of the balance points seem a little off. So much so that if I try to concentrate on where they're telling me to balance, half the time I'll lose my balance completely.
My favorite games would have to be the Ski-Jump and the Tightrope Walk.
I'd complain about the price of the package, but I plan on utilizing the board for upcoming games like Skate It and Shaun White Snowboarding, so I think the board will definitely see more usage in the future than just for WiiFit.