Well, I've spent some more time with the system now, and I think it's only fair I post an updated review:
First of all, I've gotten used to some of the things that were really bothering me (the constant "A" mashing), and even learned to appreciate one of them: the rank display at the end. For some reason it didn't click for me at first, but being able to see my progress on individual exercises is nice.
While I'd still like the program to 'build' me a routine, I have gotten used to menuing around and picking the exercises I'd like to do.
Two years ago I had an episode of BPPV (benign paroxysmal positional vertigo), which is basically a major malfunction of the inner ear (and thus balance), and something I wouldn't wish on my worst enemy. My balance never got back to 100% after that, which is one reason I was interested in WiiFit. Even though I have not logged a ton of time on the system, I can already see improvement in my balance, so this alone has been worth it for me.
I'm also more impressed with the peripheral after tonight's session: I accidentally clicked Retry on an exercise I didn't want to repeat at the time(Warrior), so I tried to fake it out and just sort of lean on the board. Even though I kept the line in the blue box, at the end of the exercise it called me on having not kept my weight evenly distributed on both legs. Despite having read otherwise in other reviews, it seems to be very good at determining if I am using proper form or not.
I'm still using free weights for my upper body workout (an area where the wiifit is understandably lacking--I'm not strong enough to do pushups yet), but it is able to give a surprisingly intense lower-body strength workout, at least at my fitness level.
My wiifit age has dropped considerably, and the system has finally acknowledged the weight loss that shows on my digital scale.
I'm finding that it unlocks new exercises way sooner than I feel inclined to try them--my balance is so poor that I'm still working on doing most of the base-game exercises correctly, and don't feel the need to move on just yet. This isn't necessarily a bad thing, and I'm sure they wanted to give people a sense of progress very early on.
Even though I've done 'real' DDR, I find the step program stupidly fun.
I may try putting the board on my actual step thingie at some point to increase difficulty.
Couple of nitpicks: I want it to stop nagging me to use it every day.
I do it when I can, and making me feel guilty is actually negative reinforcement for me. I'm sure it works for some people, but I wish I could turn it off. Also, it scolds me for being up so late at night; I wish I could explain to the program that I work graveyard shift.
Conclusion: After spending more time with the system I have greater respect for its technology, and more faith in its ability to help me achieve some body goals. It's not going on craigslist after all.