Beta 1 of LiquiBase 2.0 has been released. It can be downloaded from http://www.liquibase.org/download.
The main improvement over milestone 1 is that it can be ran against existing changelog scripts, so it can be fully tested with existing databases.
Please test this release out against your existing databases and changelog scripts and post any issues you find.
Also, do not forget the LiquiBase Extension Contest currently underway!