I don't think there IS a Premiere Pro SDK 5.5 - as far as I know there is only the one version of the CS5 SDK ("Premiere Pro CS5 release 1 SDK")
so, no there is no need to recompile/test/release.
our exporter plugin for CS 5 (compiled with cs 5 sdk) works if it is used from cs 5.5. Would you say that it is better to recompile the plugin code against cs 5.5 sdk to be used in premiere pro 5.5?
(just getting back to the office)
Sure, I'll make a post in this forum when new SDKs are released. For what it's worth, the CS5.5 SDKs for Premiere Pro and After Effects were posted within a week of the CS5.5 release.
There's no need to recompile your exporter unless there are any new exporter API features you'd like to take advantage of. Those features are described in the What's New section of the Exporters chapter of the CS5.5 SDK Guide.