FWIW, MTGOX to MTGOX transfers of Bitcoin are still enabled and working.
This means you can sell your GoxBTC for real BTC: Someone gives you a gox deposit address, you send your GoxBTC to that address and be sure to NOT check open-transaction. Coins show up instantly in their Gox accout.
People on Bitcoin talk are offering 60%, 66%, and 70% like prices.
I'll offer 85%— e.g. with round numbers: You pay me 100 GoxBTC I'll pay you 85 real BTC. You send first. This can be pretty handy if you'd like to use the current prices to get your GoxUSD out rapidly by trading for BTC and then selling that coin on something like Coinbase.
I'm mostly interested in trades over >5 BTC because I'm primarily a developer and miner, not a trader and these exchanges impose a fair amount of accounting overhead on me. I'll consider smaller offers, however.
PM if you're interested. (I'll edit or respond to this post when I'm unavailable or have changed my offer)