Many Photographers find Lightroom speed up the raw image conversion and has a user interface designed for the Photographer and their way of thinking about developing images.
I make no money from photography while Lightroom is cheaper then Photoshop it lacks the power and automation of Photoshop. If you use Lightroom you also need an image editor. Elements fills many Photographers bill there however Element lacks the full power of Photoshop and its Automation.
The way I see it there are three choices for Photographers.
1.) Photoshop extended not needed.
I have standard Photoshop since PS3
PS3, PS5, PS7, CS, CS2, CS3, CS5 and CS6.
CS4, CS5 and CS6 have more bugs then prior versions of Photoshop.
So you may be better off with Lightroom + Elements these days and save some money to boot.
Pick up a book on Processing RAW files in Lightroom and ACR. They will have more info then I can give you.