I don't have any specific knowledge of the camera companies' upcoming plans, but I do know that a few are on their way. Googling around for 'gps camera' reveals news about Sony and Casio coming out with new GPS cameras, and it looks like Samsung also has one. And then there's the Nikon that you mentioned. I think we will be seeing more of them this year.
If you're looking for a GPS photo solution right now, I would recommend taking a look at the PhotoTrackr Mini. It's basically a USB key you carry with you while you're shooting (you can just put it in your camera case) that records your location and the time, and then when you upload your photos to your computer, you also plug in the PhotoTrackr and it syncs with your photos and geotags them based on when they were taken. This way, it works with any digital camera, all you have to do is sync their clocks when you first get it.