The 8800 will recognize a 2Gb chip. Don't know about the larger chips as they aren't even available yet. When the Pearl came out it didn't support the 2Gb chip. It only took an OS upgrade, though.

As for headphones, I'd definitely wait until it comes out and see what's included. The newer Pearls are shipping with stereo headphones. I got one of the originals and it only came with the standard phone headset.