Proof #1: Nikon D3x leak from SanDisk

Here it is (and this is not a rumor): UDMA Cards will support Nikon D3x!

SanDisk UDMA Cards	Camera with UDMA Spec
Extreme IV Performance speed 40 MB/s (266x) More Info Buy Now Ducati Performance speed 45 MB/s (300x) More Info Buy No	Canon IDs Mark III Nikon D300 Nikon D3X Olympus E3 Sony A700