Will there be cameras or camcorders in the near future, that can connect usb microphones over usb?
Usb (digital) microphones have much better audio.
I seriously doubt that would ever be done, not at least for the foreseeable future.
Believe it or not, but most analog microphones are actually far superior to most USB microphones. I guess that you have not had very good luck with analog microphones. Good ones use XLR connections.