Several users in India are reporting that their Omnia W has gotten the Window Phone Tango update. As usual, the update has to be downloaded by connecting your phone to a desktop computer.
The changes this update brings include ability to add media files in MMS, export and import contacts to and from the phone and other performance improvements. Unfortunately, the Internet sharing feature that Nokia promised for the Lumia phones is not available here.
If you have got this phone, you should have gotten the notification by now. Even if you haven't, connect it to Zune on the PC and see if the update is available for download.
Source (Thanks, Sameer)