With git 1.8.2+ you can track branches as described in this answer. But compared to svn-externals without revision you seem to have to manually update your submodules when you intend to always build with latest revision of your submodules:
git clone <URL/TO/MY/COMPOSITE/PROJECT> --branch develop --recursive
git submodule update --remote
Is there a way to always have the latest revision of submodules cloned when tracking branches?
This answer suggests it would be bad and dangerous to not explicitly specify revisions for submodules. In my opinion this is true for most cases but there are scenarios where you want to track development-branches of your submodules. In such a case it's just extra work to always pull/update/commit when you want to track changes on your submodules.
