PyObjC is rapidly approaching a 1.1 release. I would highly recommend using the version from CVS at this point. It has many, many, many improvements over 1.0 and, as is typical, the module is extremely stable even in an "alpha" state.
Changes include Xcode file templates, struct support for types like NSPoint/NSRect/NSSize, bridging of SecurityInterface, improved threading support, better Key/Value Coding & Observing support, OpenGL example, ScreenSaver example, and a fully threaded WebServices example that leverages Cocoa Bindings.
See the NEWS file for full details. The list is damned impressive.
Ronald Oussoren has done an absolutely stellar job on PyObjC. Many, many thanks... someday, I hope to meet Ronald and buy him a beer or two (if that is his thing). PyObjC would not kick nearly so much ass without his contributions.