The wait is almost over.
According to Canon Japan, the Canon EOS-1D X will be officially released on June 20, 2012.
With the EOS-1D X, the following accessories will also be available: LP-E4N, LC-E4N, EW-E7, Ec-CV & WFT-E6B. The GP-E1 is listed for a July, 2012 release.
What this means for initial stock is unknown at this time.
Source: Canon Japan