the last pluggo runtime supports intel processors, and the runtime itself should work on OSX 10.8.4.
i have lost overview in which host program pluggo still works, because i am not using software newer than 5 years, but i believe live and logic should still be happy with most of the pluggo things. problems might occur with stuff like bus sends, or with installation and copy protection of the commercial version (which is not needed to run custom plug-ins)
to create pluggos you will have to install an older version of max. i would recommend to also program there. ;)