At the end of the day, I think this is a wake-up call to the Admiralty Board that what is nominally our territory needs defense, and a mobile defense, at that. With pirating likely to become much more troublesome than it's historically been as we rebuild from the Four Year War, it wouldn't be unwise to perhaps have a dedicated patrol/response ship class to keep things from getting too out of control. Something largely inexpensive and geared towards mass production, a solid amount of weaponry, and low to mid-level cargo hauling as a nice aside for those parts of the quadrant that need supplies to get there with an assured safety.
As well, I think it's time for the Federation to look at expanding our shipbuilding capabilities if we want to keep all those territories that align with us safe. Our fleet pre-war was largely quite venerable, with a core of cutting-edge ships as we went into the war, but well smaller than it perhaps should have been with the remarkable territorial gains that our diplomatic, economic, and industrial focus provided us. If we want to get back to our pre-war borders (however long that may take), we're likely to need to project an assurance that those colonies that fell under Klingon control won't have to worry about such a thing again.
It's a great thing that we have a capable ship in the Excalibur-class, but though we're pointed in the right direction, I still think we've got a ways to go.