While not yet complete, I've managed to add a very hefty chunk of Python material to the tutorial. I should be able to complete the rest over the next week or so. Would definitely appreciate feedback from any Pythonistas on the existing material.
While I hadn't used it before, I think Tkinter may very well be the nicest interface to Tk next to Tcl's (for which Tk was originally designed of course, so you'd expect a bit of an advantage). For people unfamiliar with either language, I think Python's more conventional use of parentheses for functions, the "option=value" syntax, plus other language features it takes advantage of are very attractive and win out over Tcl. The two main parts that I think Tcl does in a nicer way are event bindings and the fact you can create and geometry manage a widget in one statement, while still keeping a handle to a widget around.
UPDATE July 17/2009: Most of the rest of the Python examples and code snippets have been added.