Must support cross platform builds (arm9, mips, x86, etc) - OK, no difference from FreeBSD src base in behavior
Must work as wireless router / access point
Must have firewall (pf ?) - Now there is ipfw, think this is good :)
Build system must be simple to use - OK, currently not harder than FreeBSD build/install world
(splited) A running system must be able to update kernel/fs - Worked
(splited) A running system must be able to have packages added / updated / deleted - require writing new filesystem for NOR flash (like Linux jffs2) or biggest storage with many blocks(since 4M NOR Flash have only 64 blocks x 64K each, 8M have 128x64K)
Full support for C++ - OK (just install libstdc++)