Sun will be supporting the development of a Mac port to OpenOffice. The cited reason is that the Mac market share is growing. In the comments it’s also clarified that it’s a carbon port planned (which is great).
No timeline is mentioned, though I would suspect there’s a good 18 months before we will see anything workable. I’m thrilled to see Sun make this move. OpenOffice is a great product, and would be awesome to have in Mac OS X. Office X is not a bad product, but it’s far from affordable. Apple’s alternatives aren’t quite as robust and compatible as one may sometimes need. This is a great thing for any Mac user. Currently you can run OpenOffice through X11, but that’s a pretty bad experience.
If you remember back in 2005 Google threw some bodies at OpenOffice though it wasn’t targeted at the Mac platform. The battle against Microsoft Office continues.