I don't know if I'm all that excited about a new format. The SD/SDHC/SDXC (Secure Digital) format is said to be just as capable. Sure the new speeds are great but what happens to my CompactFlash cards when my new camera doesn't support the format. =) I know what your thinking, "deal with it, that's the game you play with technology and progress". I just prey that Canon's new line of DSLR's will give you the choice if they decide to incorporate the XQD format. Supposedly the Nikon D4 has one slot for CF and the other for XQD. I'd be happier with two slots for CF.
The XQD format is based on the PCI Express specifications and allows write speeds of 125 MB/sec and beyond. For comparison CF is capable up to 100 MB/sec with the Extreme Pro card by SanDisk. SDXC is capable of around 95 MB/sec with the Extreme Pro card by SanDisk.
dpreview.com - Compact Flash Association Announces XQD Card Format