I've been wondering the same thing. I'm just a month away from my last rt (5/24). The radiation oncologist thinks taste should start comeing back soon, but my ENT said maybe not for a year! I think it's a function of the amount of radiation received. IIRC, I received 54 gys IMRT.
In the meantime, I'm still living on Ensure and Nutren and some weight gain stuff I got at the health food store (it has lots of essential amino acids). I'm barely keeping my weight up, but don't have a lot of energy (and probably won't until I get back on a regular diet).
Riley