What my group is finding having played 4e for a couple of months now is that most of the powers are very similar to each other with perhaps one or two small differences. Sure the flavor text is nice but mechanically a wizard firing a magic missile, a ranger firing a bow, and a warlock using an eldritch blast all "feel" very similar. Sure the damage is slightly different, and there are a few slight other differences, but all in all they all "feel" similar.
Now I'm not saying that's a bad thing - They are mechanically balanced so that one character is not way more powerful than the next. That's good. It was something a cople of my players pointed out that playing a wizard and firing magic missiles does not feel special, or very wizardy, compared to a ranger firing off arrows.
My response was that instead of focusing on the mechanics, they should focus on the flavor. Describe the actions with flovor words rather than using numbers and mechanics, and the feeling should be different. That goes for any of the classes, be it fighter and paladin, ranger and rogue or wizard and warlock.