Started to do some digging on this transaction. All inputs were from mining during a short period of time.

Oldest block was mined 2010-01-25 14:03:24 (36297)
Newest block was mined 2010-01-31 02:42:28 (37356)
That's a 1059 block difference to mine their 60 blocks. So at the time they had approximately 18% of the network hashrate.

Check this out http://1.bp.blogspot.com/-0RMaiJObi8s/U-tDSbfK11I/AAAAAAAAAbU/Td_SxUQ7Kws/s1600/satoshisProportion2014-08-13.png

Which is a link from this article http://organofcorti.blogspot.com.au/2014/08/167-satoshis-hashrate.html

Anyone know if there were many others mining at that level early on? This can't have been more than one of a handful of people and satoshi isn't ruled out yet.

Edit: total math fail, that's only 5.6% of mining power, probably not satoshi, but likely another big early player.