Oh, I get the general usefulness of a cross-language VM, and the desirability of having "one VM to rule them all". But to me personally it doesn't matter so much that we get a practically working Python implementation on top of Parrot any time soon. I've looked at Python three times over the last years and hated it every time, so I can safely say I won't use it for programming ever ("ever" being the most dangerous and error-prone time-period to invoke in any statement of course ;-). Similarly, if I come across a Python app/library and a slightly inferior Perl counterpart I'll use the Perl version because if something goes wrong or I need to change it I can burrow in myself.
So while I understand that cross-language compatibility would be a very desirable thing for many people, I personally care more about Perl 6 being done. If we get a working Parrot which runs Perl 6 but only limps at Python I'd be happy and leave the people who are interested in Python to fix Parrot later (if that's possible).
And about .Net, isn't it true that it only offer interlanguage operability by turning every language into a heavily obfuscated version of C#? Does anyone actually use multiple languages in a single project on .Net? I know Jython has been around for ages, does anyone actually use it for serious work?