Straight off the Steam News site:

The official Counter-Strike Bot will be released for Counter-Strike: Source on Monday (January 17th). The Bot features enhanced abilities and will be available for all owners of Counter-Strike: Source. Also included in Mondays release is an updated version de_tides, rebuilt by Turtlerock Studios. For more information or to purchase your copy of Counter-Strike: Source, please visit http://www.steampowered.com.

I just relogged into Steam and it gave me this more detailed news:

First, we’re going to release the Counter-Strike: Source version of the CS Bot. This will be an improved version of the Condition Zero bot, and will be available for all owners of Counter-Strike: Source. Right now we’re planning this for sometime early the week of the 17th. Also included is a remade version of the Condition Zero map, de_tides, rebuilt by Turtlerock Studios.

Valve also note that there will be a new map out for CS:S in Feburary.