http://tools.wmflabs.org/pywikibot/core_stable.zip is a one-download package, which includes httplib2, so that users just have to unpack it (and no further installation is necessary). If possible, we should to the same for the 3.x releases. This might mean differend packages for different operating systems (not sure). In that case, we should focus on Windows, and ask Linux/OS X users to just 'pip install pywikibot'.
I'm not entirely sure what the dependencies are -- requests (and all its dependencies), but possibly also others?