Virginia Tech has formally announced that it has achieved 12250 Gflops/s. However, it also made the statement that "These systems were custom built by Apple for Virginia Tech utilizing dual 2.3GHz G5 processors. This configuration was developed specifically for Virginia Tech, and Apple currently has no plans to offer 2.3GHz processors in the Xserve G5 product line."
Despite their statement I would not be surprised to see these 2.3 GHz machines released in early 2005.
In addition, VT states the upgrade cost them an additional $600000, including an additional 50 nodes (which did not appear to be utilized for the benchmark).