There are slightly different ways of dealing with lighting and tonal adjustments in the latest version of Lightroom.
I thought I'd try them out on an image which has been bugging me for a while. One of its many problems is that the “vaulting” feeling here isn't suitably conveyed.
I have a while to go before this works (and may have to return to Arles for a better shot).
I haven't posted these as “before” and “after” images; they're both variants of an extensively edited RAW capture.

Photoshop CS5 from a RAW capture

LR4 edit of the above
LR has done an impressive job of bringing out detail in the shadows. Have you have any problems with LR4 removing the tone curves in your LR3 photos? That's the one bug putting me off upgrading at the moment.