This doesn't follow Yahoo's business model, except for the hosting of personal e-mail or charging for business clients. Yahoo isn't very friendly with the Open Source movement.
Yahoo likes to charge for everything, including inclusion into their search results ($50 / year).
I am very disappointed this transaction occurred, although I would have approved if I owned Zimbra shares
. Nevertheless, I would have preferred Google buy Zimbra. Google does a good job of keeping things open. For example, look at their acquisition of FeedBurner... Good bye fees, hello premium services.
At least do me a favor and open up the iSync app for Mac for the Open Source version of Zimbra?