I also pre-loaded a copy from Steam yesterday after I activated my key. Today, I launched it and Steam began decrypting. After the decryption was done, a relatively small 260MB download began. I noticed that the commentary, among other things, was downloaded during this time. So all appears to be fixed up on the Steam end.
Thanks, Frictional! All I'm hearing are glowing reviews about this. I try not to read too much because I like a pure experience, but I'll finish with how RPS concluded their review of Amnesia:
Quote:I cannot recommend it enough. So long as you don’t mind being utterly bloody terrified.
Also, the download just finished. OMGOMGOMG. Later.