I started working on that but I suspended it when we were suppose to have our first release (Feb. 2002). I hope the code lies somewhere in my computer but I'll have check. Among other things I was going to implement object-type-specific, mime-specific, and package-specific searches. I'll check and see how far I got that time.
This also reminds that I'll have to implement versioning and xml-support for contracts (so that we can say that a package provides an implementation for version X of that contract). If we are a bit patient on this one, I may have it ready before the new openacs release.