Word of advice - Buy rechargables! VERY handy and saves money.
I've been on the Wii Fit since I started SW again, it's excellent for building up exercise slowly. For example, I've been doing 10 minutes every other day, and next week I'm going to start doing 20 minutes. And the great thing is, if you don't feel like doing aerobics then you can play the games, and vice versa, and either way you're off the sofa and moving about!