The ability to use prowl is the real reason I can't stop playing druid! It's just so bloody useful!
Aside from being able to walk past a pile of trash mobs to quickly get to and kill the boss, stealth is a great OMG-I-have-to-leave-the-computer-now! button.
I was gathering stingers in the Slithering scar in Ungoro Crater when the Fedex guy showed up. I smacked the prowl button as I jumped up and ran to the door (I was scared he'd leave and I really need this parcel out today).
There were a couple hang ups with the pick up and it took me about 10 minutes to get back to the computer. And there was my kitty, unharmed and intact, sitting serenely in the middle of a crowd of wandering mobs, patiently waiting for me to get back. Sure, if one had walked over him, he'd have been discovered and killed but (oddly enough) it's never happened.
So, in addition to stealthing like a rogue (and stealth-walking even faster than a rogue), we also have the non rogue ability to tank multiple mobs. Plus we can heal!
Frankly, I can't understand why more people don't play druids!