We had a chance to meet the governing body behind the new SDXC standard and we've seen some interesting specs. SDHC currently gets to 32GB in the big SD standard but the guys behind SDXC said that this standard can get these cards all the way to 2TB.
The fist SDXC cards are expected in late 2009 and they should launch at capacities starting at 64GB. There is also a smaller SDXC called SDXC micro and this one will be mainly used by mobile phones and some other smaller devices. We’ve learned by the end of 2009 there should be a 64GB card even in SDXC micro format, while the bigger ones are expected in 2010 and beyond.
One other interesting thing is that the card should feature transfer speeds all the way up to 300MB /s.