I'm in the very early stages of bringing FreeBSD/mips on the Alchemy Au1550. Plat'Home was kind enough to put an OpenMicroServer into my hands for the port. After months of sitting idle, I've started putting the board to use again. I test booted my first kernel tonight. It is still early days, but I thought I'd mention that I'd committed the very preliminary code to the project/mips tree in svn.
As an aside, the FreeBSD/mips main development has moved from the so-called "mips2" tree in perforce to the projects/mips tree in svn. This move allows us to more easily share the work in progress mips ports that people have been asking for in the past. We'll see how well this works out and see if theory matches reality or not.