Current works about embedded SELinux
Many codes are submitted to Linux and userland community.
Xattr support for jffs2
Reducing read/write overhead
Reducing memory usage:
Improving performance in AVC miss:
Audit support for SH:
Reducing size of library: Merged to libselinux 2.0.35: 
Applets related to SELinux are merged to BusyBox in 1.8.0.
Support to assign domain to applets is merged to 1.8.0: 
SELinux Policy Editor will be helpful. See .
If you prefer fine grained configuration, Reference policy is better.
Example of porting
Technical documents, presentations
SELinux for Consumer Electronics Devices, Paper for Ottawa Linux Symposium 2008
Example of porting to SH(Super H) was reported in CELF Jambolee #18: .
Xattr port to jffs2(Japanese)
logfs, yaffs, cramfs do not support xattr yet.