You can already use XDCam with a Decklink card, we just don't have a preset for this at the moment. Because Premiere Pro CS3.2 can natively read MXF files and the XdCam format, you can import your XDCam footage onto a Blackmagic timeline, and you should be able to get real time playback.
Technical Support Consultant
Blackmagic Design EMEA
Yeah, I've tried bringing the XDCAM files into a Blackmagic preset project.
I imported XDCAM 60i footage into a Blackmagic 8-bit 29.97 interlaced project. When I'd bring the XDCAM files onto the timeline, they appeared to need rendering. Also, when I play the XDCAM files on the timeline, they keep dropping frames.