2.3.20 is the latest update for D2. You can receive the OTA update if you are still unrooted on stock ROM, or you can find the sbf file with instructions here. Whether you receive OTA or update manually, you can ONLY flash the 2.3.20 sbf once updated; using the 2.2.0 sbf will result in a brick.
There most likely will be a maintenance update before Gingerbread. If there isn't any kind of update before gingerbread, then I'll be forced to assume that the team that Motorola has assigned for maintenance updates for the D2 has been sitting back and relaxing for the past 5 weeks, waiting for gingerbread.