Currently my XT's sunroof panel is salvageable, but its frame in the roof has rusted to the point where I'm 90% sure that it would leak heavily under anything more than the lightest sprinkle of rain (the car currently lives in a carport and I don't really want to test the theory). I'd rather be able to use it but without any viable alternatives I think I'll end up sealing it shut instead.
About the only other thread I've seen here has somebody asking for a sunroof assembly cut from the roof of a donor car. Since it'll be difficult to find a used assembly that isn't already rusted to hell, I think it'd be a better idea to enquire as to whether there may be any known avenues for replacing it with new aftermarket or custom parts, unless somebody knows of a source for an OE replacement. I mean, these things are pretty much just cut and welded in place to begin with, so it shouldn't be too ridiculous of an undertaking.