Ok so despite there being a Temporary Restraining Order against the auction of the Tarbosaurus skeleton, Heritage Auctions went along with the auction yesterday. The lawyer who got the restraining order was present at the auction and when he tried to protest, called the judge who gave the order, he was ushered out and asked to leave. Apparently they have no interest in not only following Mongolian law, but also American law. They have said that the sale of the skeleton is "contingent upon resolution of a court hearing", but we'll see. For more details on the auction, see Brian Switek's blog.
Also, the Daily Mail has released some information about how the fossil came to be in the US. Apparently it was collected in 2005 by a private fossil collector in England, and then partially put together in the UK, then it was shipped to the US where it was finished. However, none of these details have been officially confirmed, but the article can be found here.
(I tried to add this update to the bottom of my previous post, but Blogger hates me and it didn't want to work, so I had to write a new post)