ASUS has one in the works but its a PCI-E 1x slot card. Or perhaps theres a few models which I think the other is PCI... but I'll bet its PC only.
http://www.theinquirer.net/default.aspx?article=38230
This is a normal thing though, they hype PCI-E to no end, and not much gets made for it. Heck its been on the go since 2005 and the only things thats been PCI-E were graphic cards, and here we are 2007 where a PCI-E sound card is about to be revealed. And now PCI-E 2.0 is on the horizon.
That is mainly due to the fact that until relatively recently there was only one PCI-E slot in a computer, and seeing as the graphics card is the one that requires most bandwidth it makes sense that it would be the first one to take advantage of the newer high speed interfaces. The same is likely to be true of PCI-E 2.0 or whatever new standard they come up with.