Announced at TechEd on Tuesday, June 3, during Bill Gates' Keynote, Brian Harry showed up the first glimpse of DBPro supported another DBMS other than SQL Server. The first supported non-Microsoft DBMS for DBPro is IBM DB2. Similar to using a provider model for data access, the DBPro team has created a provider model for database management which they refer to as a Database Schema Provider (DSP).
The idea for using the DSP is so that you can use the same database project and target any supported DBMS without having to change the user experience with VSTS.
Of course, it was not announced when it would RTM/RTW (Release To Manufacturer/Release to Web). I believe it's too early to speculate.