You haven't tried to send money from that address recently, have you?

I did a bit more transaction following ... it appears another address implicated with the thief address is 13KLNHPWLtWKTtKtr4fY5pu4Di4aQVLzPf.  This address received a coinad payout on 2013-04-10 07:54:10.

Coinad probably has the guy's email address.  Could be a dead end if their policy prevents them from handing this information out, or if they don't validate email addresses of members, or if he gave them a throwaway address.

Keep in mind, my evidence linking these two addresses is not 100% ... but it's pretty high.

Another possible lead is that the thief seems to think using Satoshi Dice a few times after a heist is an effective laundering technique.  In this transaction he apparently submitted his gambling transaction directly to blockchain.info ... so depending on how much they log, they may have the IP address of the thief.  This could also be a dead end if he's using Tor or some other proxy ... but seeing as he apparently thinks using Satoshi Dice makes tracking stolen coins harder, he probably isn't the brightest hacker in the world.

But also

'In a world first, SYTECH has announced a stolen Bitcoin tracing and recovery service; turning its decades of digital forensics expertise to tracing online Bitcoin criminals and recovering stolen Bitcoin for their clients.'

From http://www.sytech-consultants.com/blog/2013/worlds-first-stolen-bitcoin-tracing-service-and-bitcoin-data-recovery-high-profile-digital-forensic-services-company-sytech-embraces-bitcoin

If it was my coins stolen, I think I'd offer them the job if they would take no more than 50% of what they recovered.