There's really no hard boundary between 'scripting' and 'programming' languages, and python certainly has other uses than scripting. Personally I'm sure that python will find its way to the Arduino world and have its place, just as it has with .NET. There's too much goodness now in the 'py world' for this not to happen.
People always worry about scripting performance, but the worry tends to go away over time - most folk don't have to worry any more about JIT compilation and the like with Java and the .NET languages. Obviously you wouldn't want to use an interpreted language for device control, tight timing loops and interrupt routines, but for higher layers it could be very useful if there's room for the (normally) C-based engine.
http://wiki.python.org/moin/EmbeddedPython
http://wiki.python.org/moin/PyMite
Jim