The Netgate RCC-DFF 2220 is available[1] right now, and performs very well as a BSD router. It's not ARM, but it is an embedded system/SBC. I use it with pfSense, but it will run vanilla FreeBSD as well of course.
But no pretty Web UI. And Im pretty sure FreeBSD will not use the possibly existing network acceleration instructions that exists for example in the oceton soc.