Their own farm was only ~25% when ghash was near 50%, so basically the farm is ~13% of the network.
Everyone else is just using the pool, because apparently it is good and conveniant.
When they had hiccups and kicked off miners on that Monday and Wednesday they both to 27 and 29 PH/s respectively. The estimated network was 90 (ignoring luck). So it was 30%. You can confirm this with OoC or Eleuthria or wizkid.
If those new AM chips don't all head over there then we are good and should have a nice leveling out. I don't want to see Ghash.IO die, it's not like they ran over my dog. I want to see them responsive to the concerns of the community (since they currently ignore feedback from other pool ops).