I've also seen people have a single development branch and multiple release branches (imagine a 'devel' branch that everyone merges into and a branch for each release that you have, and that potentially merges back into devel if you do hot patches). It's essentially the same thing -- branches aren't really all that different than tags in git.

Yeah its basically aesthetics. I do like keeping the release identifier separate from branches though just for categorization purposes (branches = development, tags = releases)