Alex Blewitt's blog entry takes you through a technical overview on the future of Eclipse on the Mac.
With Leopard's recent release, the question of where Eclipse is heading on the Mac comes to mind. SWT on Mac uses Carbon, which is a (32-bit) C-based API that originally allowed porting between Mac OS 9 and Mac OS X. So, Eclipse is largely based on Carbon; but here's the problem. Carbon has been known to be deprecated for a while. Even some of the 'big' companies (Adobe, Microsoft) are only just moving off the Carbon train and onto the Cocoa train. Apple has tried to encourage Java developers to use Cocoa before; Apple's Java-ObjC bridge was created to permit Java apps to use NSApplication and other key frameworks.
Read Alex's entry: http://alblue.blogspot.com/2007/11/maceclipse-what-future-for-eclipse-on.html