Are you using Logic Pro in 32 bit or in 64 bit? If in 64 bit, open it up again in 32 bit, and see if the plug ins are there. At the minimum it should do another plug in scan, and then if it finds Superior and EZ Drummer, it will find them again in 64 bit.
*Superior Drummer* is a 3rd party plug-in, it is not part of Logic Studio, in case that is what you're thinking. You switch to 64 by selecting the Logic app, hit *cmd-I (Get Info)* and in the ensuing window there's a checkbox *Open in 32 bits mode* that you'll have to uncheck.