Mike Elgan is spot on here, but the same problem exists with Google, which has just killed off the desktop notifier to enforce lock in to Chrome and Google+. Twitter is slightly less evil at present but headed the same way.
I'm about ready to walk away from them all. But they still have value for me, in a range of different ways. Until I have viable alternatives to build on, I am locked in. But at least now I know I'm looking for a solution. One thing I know from previous network migrations - you can't simply port an existing network to a new location, you start again each time, not quite from scratch, but close enough.