The recovery thing is this:
http://forum.doozan.com/read.php?4,7915It uses mtd1 and mtd2 to boot to a local NVRAM-based custom Linux distribution that offers the usual set of "rescue CD"-esque tools directly on the device - very, very handy when you have a box that won't boot because something stupid got stuffed (and directly SSHable!).
No special handling required by mainline (it's reasonably trivial to set the appropriate envvars), but it looks like when mainline installs, it completely takes out mtd1 and mtd2 (unless I read the tea leaves wrong and mistook an offset for them being plowed - if mtd1/2 is left alone during mainline installation, then ignore this whole thing =)
Rodney