Other than "multi device preview" I think Android studio has all the features that IDEA13 offers for android developers. IntelliJ is great and I do all my Java/Groovy based development from it, but I'm not sure about buying the license just to go upgrade to 13
Database support has always been an Ultimate Edition only feature. However, nothing prevents someone from building their own plugin. For example, there's a third party one for MySQL that's fairly popular.