The Lightroom developers have listened to customer needs and finally a perspective correction for "converging lines" implemented. That alone justifies the update for me, as is already worth the update from version 1 to 2 for the range correction and the gradient. I need as no longer an external image editor (GIMP in my case) to dodge, which greatly simplifies the workflow. The desire for a shift lens is moved for my needs in more remote, and the handle for Super Wide rarely necessary.
I would say now Lightroom is "grown up".
But that's not all: When I noised trial basis shots that I took with the Nikon D300s with ISO 3200, I could not believe my eyes. Perhaps now saving on a Nikon D700 no longer quite so urgent ;-)
The third highlight is the video import. Since I use the D300 with video function has always bothered me that we had to secure the video from the card separately. Now I can actually manage in the Lightroom catalog.