I'd Skip the PW. Too many issues with a third party unit. With the Canon 580EXII, for example, it has a range of 40 ft max, unless you put the weird RF sock on it or pay to have the flash modified.
Other triggers do not have the issue, but still seem to break with every new generation of camera bodies. At some point, they will not update them any longer and you will have to buy new.
If you need a flash, get one, don't wait for a rumor to materialize. Some have been waiting 7 years for a new 100-400L. However, it currently had no real competition, its the best of its kind.