This question is more about Open-Source etiquette, and the new approach that the likes of github and gitorious gives to collaboration and source ownership. Can you just take any Open-Source project from somewhere else (e.g SourceForge, with a clear project team and community) and put it into your own github repository, provided that you respect the terms of the original license? And if yes, do you keep your version under the same name, or change it?

I somehow have this nagging feeling that this is rude, and yet it is open-source after all...