This is no big surprise - based on all the reporting I saw on this, the decision to move was a political decision rather than a technical decision with political support. In other words, the city decided to migrate, and only then did they find out what it entailed. This is similar to many of the rewrite efforts you saw in the late 80's, moving from (insert tool here) to Java. A decision was made for political reasons, and only later were technical issues discovered.
Contrast Munich's head first decision with what the city of Paris is doing:
This hasn't stopped other cities, states and countries from giving open-source software a try 14 or at least a second look. Paris recently revealed it was studying ways of moving its 17,000 government PCs from Windows to open-source
Instead of just making a gung ho "let's go" call, they seem to be studying the issue so that they can see what pitfalls and issues there might be first. Now, let me relate all of this back to a series of posts I've made (here, here, and here) over the past few days. Shops that just decide up front to use the currently fashionable language and/or tools - without even looking at other possibilities - do themselves no favor. Heck, they may end up going with Java or .NET after looking around - all I've been trying to point out is that too many IT shops don't even look. With the perceived cost advantages of outsourcing, how bright is it to close off possibilities like that?