[thedoc (OP)]

Daniel asked the Naked Scientists:
   As the universe expands. Will the cosmic microwave background red shift into the cosmic radio wave background?
What do you think?

[evan_au]

Yes, the current favorite theory about the end of the universe is called the "Big Freeze", where the temperature of the CMBR shifts from its current 2.7K down towards absolute zero.

The peak wavelength of the CMBR will shift from the microwave band down into radio waves and then into ultra-long radio waves which are undetectable with an Earthbound antenna. But this will take a long time.
See: https://en.wikipedia.org/wiki/Future_of_an_expanding_universe

If the acceleration attributed to Dark Energy continues, some suggest the occurrence of a "Big Rip", which will have the same effect, but much sooner.