It's a legacy of the import system and I'd rather see it go.
The non-alphanumeric argument is pretty weak though.
I don't know enough about asyncore/chat but SimpleHTTPServer is quite spot on. It's fine as a development tool, but really should be avoided in production environments.
(btw, Twisted is awesome. A comparison with Tornado only compares a small part of Twisted. Sure it was developed pre-PEP8 but it's still solid kit. Nothing quite like it on the Python market, afaik. Also the docs have gotten a lot better in recent years.)