Mtgox is now having BTC withdrawal problems.

Two interesting posts on Reddit:

One claims that mtgox tried to double spend:

http://www.reddit.com/r/Bitcoin/comments/1jaiow/mtgox_makes_double_spend_transaction/

Another speaks of missing transactions:

http://www.reddit.com/r/Bitcoin/comments/1jacs7/made_two_transfers_mtgox_blockchaininfo_only_one/

I just sent one coin to another 20 minutes ago and it has not appeared on the blockchain despite two blocks mined in that time.