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…
Legally, yes you can, since the source code is freely available and you are (generally) allowed to redistribute it. Is it “kosher”? I guess that depends. A lot of people will mirror a repo on GitHub, especially if the canonical repo is only available as an SVN (or other) repo; in that case, the person who puts it up on GitHub will usually keep the same name, with a note that it is a mirror of the official repo.
If you’re not only mirroring but forking the project and putting it up on GitHub, you should probably change the name of your fork (unless you fully intend and expect to have your changes merged into the official repo at some later date).