IGN Manhandles the DS
Thanks to IGN, who wrote "The Nintendo DS is being prepared to ship out to retailers for its November 21st launch. We were able to get our hands on the final, boxed units two weeks before the system's official release date, and we wasted no time ripping the packaging to shreds to show you exactly what you get in the box."
DS has GBA compatibility.
From what I've read, the backwards compatibility of the DS stops at GBA, so GB and GBC games are being left behind.
Not only that, but it is *not* compatible with multi-player GBA games.
I was really hoping to play those over the wireless connection. Ah well.
I haven't gotten a new handheld console since the GBA came out, so I'll be skipping the SP and moving right to DS. :P). Not so if you stick to the SP/GBA.
What tickles my fancy is the dual screen setup, the better graphics, the wireless connectivity, the touchscreen and the standard backlight(finally!).
Also, of course, all those games that will come out for DS that you won't be able to play on an SP/GBA. If you get a DS you can play all the nifty DS games that will most likely come out, while still retaining the ability to play that nifty GBA game that you might want without any major setbacks(unless you're a multiplayer whore
These are my reasons only, though.
Well, existing multiplayer GBA games aren't compatible with the new GBA wireless adapter (Pokemon Fire/Leaf and the new Mario Golf are the only ones I'm aware of that use it). Nintendo's got a history of being slightly annoying in that department, but being able to play the GBA games at all is good enough for me.