Not yet, but it's possible somebody will ship one. Socket 754 PCI-E boards are suppose to be coming.
Another possibility for him, though, is the MSI RS480M2-IR. It's a Socket 939 Athlon 64 motherboard with a 16x PCI-E graphics slot and an integrated Radeon Xpress 200 graphics processor. Your friend can run the IGP until he can afford to spring for the PCI-E card of his choice.
The Radeon Xpress 200 graphic core fully supports DX9 and the framerates are pretty good on most games if AA/AF isn't turned up too high. Far Cry and Doom 3 are playable at low res/med detail, but other games like Half Life 2 and Unreal Tournament 2K4 are quite playable on the integrated graphics core.
Another choice for your friend to consider is simply sticking with AGP. Almost all of Nvidia's 6000-series cards are available as AGP as well as PCI-E. The 6600GT is benching faster as an AGP solution than it is as a PCI-E card in many tests. ATI is also starting to ship X800-series solutions in AGP format.
PCI-E may very well turn out to be no real upgrade at all. A socket 754 motherboard with an AGP graphics slot looks a lot less obsolete than it did 60 days ago.