Not sure if it will move, but the PTC Product Calendar now is listing a release target for the next version of Windchill.
I'm also starting to see support documents discussing Creo Parametric 4.0. I wonder if maybe that will be released around the same time...
In some ways it's kind of funny. We are finally getting ready to jump from Wildfire 5.0 to Creo 3.0. Maybe we should wait a little longer and just go from Wildfire 5.0 to Creo 5.0. Of course by then it will probably have it's name changed again. 