I don't really see the point of all these system redesigns. They frustrate me. Like the GBA to GBA SP made me go "-_-;", considering I already had a GBA, so I didn't see the point of "upgrading" it when the only real difference was the shape of it (which I like the original GBA shape better; it feels more comfortable) and the backlit screen. The only pro to me was the backlit screen, and that wasn't worth buying an entirely new GBA for. Had I not had a GBA, I probably would've gotten the SP.
Anyway, I really don't see the point of the DS Lite. From what I've seen, it's just...slightly smaller. And the buttons are arranged slightly differently. I could be wrong, though, but I don't know. I'm also not usually one for "compact" handhelds.
I'm perfectly content with my DS. Everything about it has been great--the design, shape, color, screens, lighting, rechargability, etc. I can't think of what could be improved upon, other than the ability to play GBC and GB games.
While I like the ice blue and navy colors best for the Lite, I voted "none", since I don't intend on buying one.
Edit: What REALLY makes me go "wtd" is the Game Boy Micro. I seriously don't see the point of buying something like that, since it doesn't do anything the GBA or SP can't do, and especially since it's so incredibly small.