I guess Android has a different kind of sandbox than most typical software fault isolation based sandboxes (e.g. NaCl).

Its more reminiscent of plan9's per process namespaces than anything else. http://plan9.bell-labs.com/sys/doc/names.html

Regardless, the main issue that was preventing Go from running on Android was the linker's inability to link go pkgs as a shared library. Fortunately support for external linking on ARM is scheduled to land in the go1.2 release.

http://tip.golang.org/doc/go1.2#gc_changes

When it comes to go support for NaCl, llgo is imho the most promising solution for that. http://github.com/axw/llgo