Steam News has word on a new version of the Steam client that's now automatically available. Here's the change list.
Fix a bug where installing a game with a demo may not initial install all content with some left to download on first launch
Fix a bug with ISteamNetworking getting available packet size for Steamworks Partners
Steam Cloud improvements to support save games in more cases for Steamworks Partners
Windows: Fix a case where minidumping due to an error could deadlock the client on startup or shutdown
Windows: Fix a memory leak that could lead to too much memory used or a crash if you remained in a busy group chat for several days
Mac: Fix client errantly opening a script in a text editor at startup (rare bug)
Update is kinda wonky for me. I have no connection to friends or anything. Trying to sign in to add Dead Rising 2 to my wishlist is telling me incorrect login as well. Ugh