HBO Go airplay

I am unable to use the new HBO Go airplay feature with my apple tv 2 that has atv flash installed.  I CAN, however, use it on my apple tv 3 after installing the apple update.  Was the new atv flash update supposed to take the place of the new apple update that gave us bluetooth keyboard and other features?  If so, something is missing on the HBO side.  Also, It said atv flash was installed from my computer ok, how to check at the tv?  My plex is still working and I thought that was an app that broke after installing update.

Did you just update ATV Flash, or re-jailbreak your ATV2 with the 5.2 firmware?    It is the 5.2 firmware that gives the extra features, and also breaks many apps such as Plex and XBMC.  You mention you are running Plex OK which suggests you on a firmware release earlier than 5.2.

I only updated atvflash. That explains everything. Any eta on plex update?

For Plex update ETA you need to ask in the Plex forums to get any definitive estimates.