They have but it's still in progress. I've only done it rarely in PS but it is super easy to round trip from Lr to PS if you have both so I haven't given it much work in Lr. They really beefed this up in the latest Lr but room to grow for sure.
http://tv.adobe.com/watch/getting-started-with-adobe-photoshop-lightroom-3/lens-correction-perspective-correction/
I suspect that that is going to be a big focus of Lr4:
-Perspective correction + warping for effect
-Automated montage / pano stitching
-Single shot and multi shot HDR
All of which require PS now but you can see they are laying the tracks to make this portable over to Lr.
If you do a search on the web you will see some blue sky engineering videos of adobe doing focus stacking too, which allows for stitching / layering for an infinite focus effect. Will see if I can find it on youtube unless one of you pulls it first. For me the interesting thing isn't in creating greater depth of field but in using this tech to more accurately create subtle (and not so subtle!) defocusing to bring the subject into a thin slice of focus and automatically creating beautiful artificial bokeh which consumer zooms are currently incapable of doing. So you could make a convincing looking fake f1.2 aperture slice from a zoom that maxes out at f3.5 say.
http://en.wikipedia.org/wiki/Bokeh
Don't tell John Rice I'm geeking out over the thought tho! =)
