LVDS fan-out buffers can be used to make copies of the clock coming from one of the oscillators approved for use with Virtex-II Pro's RocketIO transceivers. Xilinx has not tested these buffers with RocketIO, but they do meet the requirements for the reference clock.
Micrel (http://www.micrel.com) makes LVDS fan-out buffers with very low jitter. The peak-to-peak jitter is either 1 ps or 10 ps, depending upon the parts. The buffers also have fanout for 1:4, 1:10, and 1:22.