It better have like 40 hours of battery life like the NGPC in order for me to even justify making a new DS Lite purchase. I'm already on my 3rd (Sold off DS Phat, Sold off white DS Lite to get the pink DS Lite)
I also heard that they were looking at using larger screens. Even that both would be touch capable. Sounds like BS to me. Larger screens would make the games look worse, and dual touch screens would be useless unless you had games specifically made for it (games would then not function on the older models). Personally, I think Nintendo won't be making any real revisions for sometime, and if they do, it'll probably be something like the GBA Micro (a lame revision to bloster sales before a new handheld drops).
I remember hearing that the two screens would be very close together, and that the gba compatibility would be dropped all together. I really wish they'd add the gb/gbc support back, and let me map my buttons so I could use y/b instead of b/a. I always wished I could have mapped l/r to the face of the system for kof or sf2tr.