Turns out that while Ubuntu and SuSE said they were distributing OpenOffice, they patched the sources heavily and shared it: Novell maintained the Go-OO patch set for a while. When Oracle came along, they basically put a stop to it: they said it was trademark violation. So, they took their patches and forked the project, and the result was LibreOffice and the DocumentFoundation.
People have said that getting changes back upstream Sun was much harder than it should have ever been. The source code is also complete shit: see LibreOffice's "Easy Hacks" page for some perspective.
When you also consider that there were a set of patches that most distros GO-OO, which have already been merged with libreoffice, distros haven't been shipping the real open office for years.