Timestamp hashes are still already possible:
txout: 0.00 <appid, hash> OP_CHECKSIG
If there's an actual application like BitDNS getting ready to actually start inserting hashes, we can always add a specific transaction template for timestamps.
I like Hal Finney's idea for user-friendly timestamping. Convert the hash of a file to a bitcoin address and send 0.01 to it:
The money will be lost forever, as there is no way to spend it further, but the timestamp Bitcoin address will remain in the block chain as a record of the file's existence.
I understand that this is arguably not a good use of the Bitcoin distributed database, but nothing stops people from doing this so we should be aware that it may be done.