I think the release of IB is expected to be at the end of April now, so if you are happy to wait then fair enough.
That said, If you are going to wait I would personally just hold off on buying the board and get one at the same time as the CPU. The Z77 and Z75 boards with native USB3 support, native PCIE gen3 (and possibly performance/overclocking benefits as well) will be available to buy then, and it is possible Z68 board prices will go down, since they would be last-gen at that time.