IronPython 1.0 Released
For existing Python developers, this means a lot more than simply having access to the .Net Base Class Library. According to Jim Hugunin of JPython fame, it also means Python programs can run of approximately 1.7 times faster over that of CPython, the native C++ implementation. Of course this is a benchmark figure, so your results may vary.
This is the first time Microsoft has offered the source code for one of its programming languages. Released under Microsoft's Shared Source License, anyone can download and examine how the compiler was constructed. This alone should make it easier for developers of other dynamic languages to build CLR compatible compilers.
IronPython does support the WinForms namespace, which gives Python developers the ability to create traditional windows applications.
Because IronPython doesn't support C++ extensions like CPython, the existing GUI frameworks such as wkPython or Win32All will probably not be available.
Something to note is that IronPython isn't supported on the .Net Compact Framework, nor does it run on earlier versions of the CLR.
This is because it heavily leverages the new dynamic language support only available in CLR 2.0.
According the to official FAQ, there are still some unresolved issues. IronPython does not support CPython's PYD libraries nor can it create DLL files of its own. The latter means that while IronPython can use code written in other .Net languages, the converse isn't true. More information on known issues and CPython compatibility can be found in the Differences and FAQ documents.