Oh, I forgot to say that I created an svn branch including my work: import_unicode.
http://svn.python.org/view/python/branches/import_unicode/

You can try it if you prefer svn to an huge patch.

I created a branch so you can follow my work commit by commit using svn history.

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The patch is not completly done. There are still remaining FIXMEs. Some FIXME are not bugs, but improvments. The most important FIXME is to restore the support of bytes path in sys.path. I removed it temporary, because it was easier for me.