20th May 2010 Team Fortress 2 and Counter-Strike: Source Beta Update Released
Updates to Team Fortress 2 and Counter-Strike: Source Beta have been released. The updates will be applied automatically when your Steam client is restarted. The major changes include:

Engine
Improved crash reporting system to enable more detailed crash reports
Fixed a client crash caused by a buffer overflow while processing temp entities

Counter-Strike: Source Beta
Fixed not being able to add bots to the game using the Create Server dialog
Fixed some movement ConVars to match the current Counter-Strike: Source settings for default values and flags
Fixed several rubberbanding/stuttering issues with objects and players
Fixed several ConVars (sv_accelerate, maxspeed, etc.) being hidden
Fixed bloom problems
Fixed a server crash caused by malformed client autobuy string
Fixed developer console output being on by default
Fixed "Report Bug" in the main menu not working
Fixed the missing icon for the desktop shortcut
Fixed the "rebuy" command not buying the correct items depending on the order they were purchased in
Fixed the clock image in the spectator HUD being clipped

Team Fortress 2
Fixed a case where the Spy could start taunting and cloak at the same time
Flamethrower changes
Increased base damage 10%
Afterburn duration increased (from 6 to 10)
Flares that hit a burning player at mid-to-long range will crit
Reduced Backburner damage bonus from 20% to 15%