As with any Jive customer who's implemented sophisticated customizations within their Jive SBS platform, care must be taken to test any new version to make sure the customizations still function properly and that new functionality is ready to be utilized. That's why we'll be upgrading the Jive Community (Say "goodbye" to Jivespace and Supportal! as Jivespace) to 4.5.x around the end of August, after we make sure the Jive Support Community (formerly known as Supportal) functions properly on that release, among our other customizations.
Until then, feel free to comment on this blog with which Jive SBS 4.5 features you can't wait to use here in the Jive Community, or with any questions you might have about Jive Community's upgrade (for questions re: your organization's upgrade, please post them in the Jive Support Community discussion area). We're listening!