I suspect it's almost inevitable that Canon will release a high MP body in the near future (<1 year), if only to compete with the D800. But...I think it's unlikely that that high MP sensor will be put in a 1-series body - rather, it will be in a 5-series body and have a relatively slow frame rate (~4 fps or less).
So, if you're looking for 1-series durability and speed, get the 1D X. I love mine. If you don't need robust build or a fast frame rate, but higher resolution is at the top of your list, waiting for Photokina might not be a bad idea (but in that case, you'd likely be debating the purchase of a 5DIII anyway, not a 1D X).