I've read one of the reasons WHY usb 3.0 is in endless delay is that the chipset currently developed can not get full spec bandwith utilization and that successive chipsets will get steadily better.. The whole point of getting usb was to (try) make sata 1-2 and usb 1-2.0 obsolete. Bandwidth is supposed to be in the 10gigabit range although devices certainly won't spit out that kind of bandwidth all by themselves, they are supposed to co-exist to suck up that thruput.
I'd rather see this on the motherboard early next year than in add-on cards.. because motherboard designers really suck at making pci-e slots far enough apart so that they don't overlap with a video card. Generally on most boards, you lose a 1x pci-e slot during this tradeoff especially if you sli-crossfire config. When properly config'd a mb/ should have 2 x16 slots back-to-back (but far enough apart for cooling which means dont make them fatter than a 3.5" hard drive, dummies-- make cooler running chips!), an X1 or X4 slot, then 1 or 2(if there's room left) for legacy pci 2.X (without costing mega bucks $$)
** Then again, why not just make 2 x16 slots for video, and an x8 slot which can also pair down to 2 or 3 legacy pci slots with an adapter (yeah, how would that look? well, the x8 slot would utilize the next breakout on the case for wiring, obviously) 2010 is the year of new mobo sockets anyway.. might as well toss legacy pci as well.