I used to only use Photoshop for image editing, too. Some friends suggested LightRoom, but I really didn't see the need -- how could an application much less powerful than Photoshop be of help?
Then, I took the time (a couple of days) to learn it (Scott Kelby's book (http://www.amazon.com/Photoshop-Lightroom-Digital-Photographers-Voices/dp/0321700910/
) is awesome
by the way). Now, I can churn through more photos in the same amount of time. Moreover, the changes are non-destructive (i.e., the original file remains untouched).
In addition to the editing features, being able to tag photos with keywords means I can easily find all my photos that are animals, or more specifically birds, or maybe just parrots -- without regard to when I took them or where on disk they live.
So, fwiw, taking the time to learn LightRoom might be well worth your time.
Your mileage, of course, may vary