OpenGroupware revision 2181 closes Bug#394. It is now possible to set a default to determine the default storage backend for new projects. (Wow, with GNUstep based stuff one ends up using the term "default" so often in different ways....)
To select database as your default project storage backend:
Defaults write NSGlobalDomain OGoDefaultProjectStorageBackend Database
To select the filesystem as your default project storage backend:
Defaults write NSGlobalDomain OGoDefaultProjectStorageBackend FileSystem
Most people I assume will want "Database". Remember that default values are CASE SENSITIVE!
If you (at least on r2181) attempt to create a project without selecting FileSystem/Database you'll get a popup warning: "Please specify your project storage!" If the default is set then the preferred storage backend is preselected (and can be changed).
Aside: If you use FileSystem projects make sure you have the SkyFSPath default set and that the referred to directory has the correct permissions.