Lightroom is an app designed only for photographers....
And that will hobble it I think - Even photographers need a DAM app that can recognise files other than just images. As Ian mentioned above, LR has some recognition of WAV files, but as it's hidden away, no-one seemed to know! Which seems to be a very LR trait. Lots of very clever things in LR, but it can be hard to find them at times.
Back to other file types. I used LR to import images off my compact for the first time the other day, instead of Bridge and nearly deleted the movie files created by the compact, when the import/copy was finished!
Slideshows are also becoming more common with photojournalists, so being able to handle soundfiles in the library would be a good way to deal with the job. In fact a wave/loop editing module would be a fantastic addition to LR. And for those who will stamp their feet and say that's not for photographers, simply ignore or do not install the module. LR would be an even better tool if it was a proper DAM app and didn't care if a file was video, sound, stills or artwork.
A Soundslides module or a DVD module or a [basic] video editing module would make LR into a very powerful programme indeed. Not so focussed on just photography, but if you just enable/install the modules you need/want, then you can be as streamlined or powerful as you want.
The reason why PS is so good now, is that people other than Photgraphers guided its development. And photographers really benefitted from these other ideas. Even the non photographic text pallette is very handy for producing copyright marks or logos on your web images. The drawing tools can produce frames for prints, layer comps can make for one single PS file rather than several variations and so on.