Zimbra is a phenomenon with enough momentum to outlive a lot of hurdles that could be put ahead of it.
The enthusiasm and effort that these people have put into their product has resulted in a rapid development cycle, which is well supported.
Zimbra is a matured product, if development slowed or even stopped, then I have no worrys leaving the existing code in place at clients for at least three years.
Zimbra key people agreed to stay in place for three years after the Yahoo buy out I think they have the strengths to argue their corner.
Worst case is we will end up with an open source version and the Network Edition will fade after its product champions move on.
These are risks in any scenario.
So I am very happy with what is going on now, I for one intent to continue installing Zimbra open source and Network editions.
Novell have made similar efforts with open source and for sale editions, they
also have made some interoperability deals with Microsoft.
Open mentality needs to be absorbed into Microsoft through every possible method.
Let Microsoft own Zimbra, and may be Zimbra can teach Microsoft a thing or two.