JetBrains PyCharm is a new Integrated Development Environment for programming using Python with the following key features:
- Intelligent Editor: for Python with code completion, on-the-fly syntax and error highlighting and code inspections
- Code Refactoring: including rename, introduce variable, introduce constant, pull up, push down and others
- Project and Code Navigation: specialized project views, file structure views and quick jumping between files, classes, methods and usages
- Error-Free Coding: on-the-fly code analysis, error highlighting and quick fixes
- VCS Integrations: out-of-the-box support for Subversion, Perforce, Git and CVS with changelists and merge
- Cross-platform: works on WIndows, Mac OS X and Linux
Sounds like it has a lot of promise.