I traded in my DS lite for the DSi. I debated whether to wait for the next Nintendo handheld system or upgrade now. The L trigger stopped responding a few weeks ago, probably due to massive pokemon playing and that I take it everywhere. I use my DS every day, so I decided I should upgrade rather than find a way to fix it.
So far, I'm very happy with the trade. I like the new matte finish on it, as it doesn't feel like it could slip out of my hands easily. I didn't think the voice editing and camera stuff would be interesting, but it's pretty fun to mess around with.
I also downloaded Art Style: Aquia and the browser. The browser's kind of slow, but it's pretty neat to have. I didn't know if I would enjoy Aquia, but I've played it more than Mr. Driller: Drill Spirits, which I picked up at the same time. I'm loving the music for it as well. I still don't know if I want to download anything else yet. I know Warioware is short, and I don't know if I'll get much use out of Mixed Messages. Hopefully, Mighty Flip Champs will be coming out soon.