Here are the patch notes, in case you're wondering what 1.22a does. By the way, connecting to Battle.net will automatically download and install this update.

- There is now a replay auto-save feature in the options menu. Replays
are automatically saved to the "replay" folder.
- The game is now automatically saved in the event of a potential
disconnect. These saved games are placed in the "save" folder.
- Player color selection can now be limited by the number of players in
the game using an option in the "Advanced Options" screen during game
creation.
- Added an option to always show unit and building health bars.
- You can now enable and disable the display of minimap signals
from players and other observers using chat commands:
/showminimapsignals and /hideminimapsignals.
- Added a new in-game cheat "maxfps" to limit the maximum frame rate to
the given number. Example: "maxfps 30" will set the maximum frame rate
to 30 FPS.