Right now I am developing plugins-module for Greenbox Framework, and I spent so many times to discover how NetBeans works internally, its details, and a lot of related issues.
Ofcouse, I lot of users and customers asked me for an Eclipse Version, and I am trying to do almost the same, but NetBeans and Eclipse are completelly different platforms. Then all work I spend on NetBeans, anybody else will spend porting to Eclipse the same things I did.
However, there are a JSR which describes how plugins, extensions, modules, wizards, menus and so on...Should work, this JSR 198.
Unfortunally I can't say if NetBeans, JBuilder, Eclipse, IDEA, JDeveloper (big players) are at least really tryng to finish and use this JSR... Would be awesome see the WORA concept working for Addon tools.