From what I've read Sandisk, Arri, Phase One, Lexar and Sandisk support CFast 2.0.
XQD was developed by Sandisk but not manufactured by them. Lexar and Sony are the sole XQD memory card makers and Nikon D4 the sole camera supporting it. Some months ago BH Photo claimed that Lexar discontinued XQD but Lexar rebukes this.
Only XQD you can buy off BH is from Sony.
CFast is not available on BH as of my writing.
My thoughts are the next 1D, 5D and possibly the 7D will support CFast if they start allowing uncompressed video straight to internal memory card or 4K resolution recording.
CFast would also be required if Canon were to adopt a TLR-like technology to attain higher continuous RAW fps. As I see it memory card read/writes are the main culprit holding back cameras.
XQD and CFast are based on PCIe and SATA technologies. As such are restricted by the same limitations. Like SATA rev 3.0 peaks at 600MB/s and PCIe rev 3.0 peaks at 800MB/s.
Next step up has both CFast and XQD peaking at 1.6GB/s. I think they will be updated once 8K resolution recordings become popular. In say 5, 10 or 15 years from now?