I did a test, with 1 BTC. I sold it on MtGox (I think for like ~100 USD), and had it waiting in a transfer queue in MtGox for over 3 months, waiting on their bank to complete the wire transfer. In late October, I finally asked them to cancel the USD wire transfer and convert it back to BTC, so I could use my BTC somewhere else.

This is a great idea but there's no way to get USD out of MtGox without growing old. Your money can work better for you elsewhere.