This is the second alpha release of the drupalcon changes that many people in the 7.x-1.x dev branch have been using with COD.
Major updates here include better timezone handling and the session evaluations feature backported from drupalcon.
If you're using any version of COD for your site before Beta 9.1 or 9, you should stick with the 1.x branch, unless you do extensive testing first. This 2.x can potentially break the upgrade path. If you're starting new, use this version of COD.
Changes since 7.x-2.0-alpha1: