You could have checked previous questions in this section.
Microsoft has never set an exact date for Windows 10 Mobile official release, wo all we can is guess. Most of us think and believe that it is coming somewhere in mid December, prretty soon i'd say. And this present build 10581 is probably going to be marked as the official, first wave, and that's the one you guys will get. If you've waited this much, then you can make it 15ish days more.
To sum things up. Your 920 is getting WM10 update, and will get most of the features that all other phones will, and this update is probably going to take place in some 10-15 days.