My full braindump on the IronPython keynote looks very similar to Jeremy's, so I'll just highlight the points that stuck out to me as a first-time PyCon attendee and relative Python newbie:
- The Peedy demo where he interactively called other .NET components to control an animated character from the Python interpreter was silly but impressive.
- He made the whole IronPython concept seem incredibly sensible with one rhetorical question:
Why not leverage 100s of man-years of VM development?
- IronPython is markedly faster on PyStone than CPython.
- Calling C# code from Python and vice-versa seemed as easy as you could hope it to be.
- It was very impressive to see the multi-language debugger seamlessly expose an exception stack trace that started in C# and crossed over into Python. Such a debugging environment is way, way better than the world of CPython + SWIG + gdb.