This site - http://www.forbes.com/2005/10/20/cx_gd_1024featslide_comm05.html provides some interesting commentary on future communication devices and the changes we could see in the future.

The device I would love to see would be a phone (Orange C500 sized) that plugs into a bigget unit to use as a PDA with a larger (VGA) screen that could allow you to have a larger device when you needed it but a smaller phone when you wanted that form factor.