Until we have official designation under the tax code, I do not believe he should need to declare it at this time.
That's a very dangerous strategy! If you need to buy a lot of USD, make sure you talk to an accountant.
I've never sold bitcoins for dollars and hope I never will. I had no idea I was interested in money until I had the opportunity to use it freely without running afoul of arbitrary, confusing, detailed, and sometimes retroactive rules. It was a chilling effect; the potential gains from managing money properly were outweighed by the risk of imprisonment if I messed up. Every time an accountant or lawyer said "it depends" I cringed.
No way do I want to go back to that minefield.
This was just an opinion not a strategy. I agree however, you should talk to a qualified financial professional about these questions. You don't want to be caught in a tough position.