Personally, I have never used Adobe's ftp server, but I checked out the recent Release Logs and End-of-Life notifications and didn't see anything related to this server...
That said, Adobe has been trying to wean itself off the old "Omniture" nomenclature for some time... perhaps this was an oversight? I did a DNS lookup for omniture.com and couldn't find any records... it's possible that someone removed it from the DNS without realizing that the FTP was still active and in use?
This sounds like something to contact Client Care about...
Good luck!