Thinking from the team management perspective, the most important features for me are

• support for multiple development languages
• support for integration with 3rd party and in-house tools:
  • ability to customize based on data stored in files and environment variable - ideally without having to copy data stored elsewhere for other tools into a tool specific format.
  • ability to accept inputs and send outputs to third party tools
  • ability to customize the entire menu - not just a dedicated list of plug-in menus
  • ability to integrate custom version control systems, build systems, debugging tools, diff support, refactoring tools, project management tools, and so on.
• ability to set site wide defaults
• ability to bundle up and distribute customizations
• ability to layer personal customizations on top of sitewide defaults
• not too difficult to learn customization/integration interface

If all of the above exists we can make, buy, or download the rest - syntax highlighting, etc.

Nice to haves would include:

• trouble-free support for local editing of remote files
• built-in syntax highlighting that can be replaced with custom tools.
• built-in jump to error API (to facilitate integration with custom debugging tools)
• built-in space-to-tab management
• A robust plug-in/add-on development community
• A customization language that lets team members customize their tools using whatever language they typically program in. A second best would be a language that is commercially important to us so that form-fitting tools to one's work habits also encourages/reinforces languages that I would want all team members to know. An IDE with Perl as the customization language would definitely pass that requirement!

Best, beth