This has me very excited, but a little worried at the same time.
Without a doubt this will be my next camera, I've held off on getting the 5D Mark II because I don't want to risk it with the AF system for shooting gigs. I stupidly bought into the 60D years ago and am now stuck with a bunch of SD cards, it'd be amazing (for me) if this new FF camera used SD cards but I have a feeling it won't.
So you are exactly like me, Ive held off on getting Mk II because of AF. Im shooting a lot of gigs and DJs/club stuff - so 7D-like AF would be really helpful. This new FF seems like a good "walkaround" camera for me.
Well, there are CF-SD adapters - so nothing to worry about. You can find adapter on ebay for around 18 USD. As a 450D user Ive got 2x 8GB SD and one 16 GB microSD, so a lot of space - I can see your point.
EDIT - ofc, CF card are faster then SD cards, so if you want to shoot in RAW and in burst mode - with such adapter your card will limit you in terms of speed (mb/s). With 600x CF card you get a lot faster speed then with any SD (fastest SD - class 10 - 10 mb, CF UDMA 6 - 133 mb).