Surprisingly, the decision for the city to move to Google wasn't based on price in this instance since both Microsoft and Google charge pretty close to the same for their various offerings. According to Bill Oates, CIO for Boston, the decision was based on the city's belief that Microsoft could no longer meet their fast paced, changing, needs for a secure cloud environment.
In other words: they don't trust Microsoft. And why should they?
Over the last few years, the company has played a dangerous game of trying to straddle both the enterprise and consumer software worlds. Some of those gambles, like Office 365 have paid off, others, like Windows 8, have not and the failures have began to shake everyone's confidence. Until Microsoft decides what it wants to be when it grows up, I suspect they will continue to lose customers to hard-core enterprise companies like Google who have a more unified and directed approach to their software and web offerings.
Wake up, Microsoft! You can't straddle both worlds for long. Jump into the enterprise hard and start to win back some customers. You're playing a deadly game and, right now, you're losing!