Lol, funny question.
Here's why I chose a Warrior over a Pally... I did not want to heal.... period. I always dreaded having to keep people alive, so easy choice. lol.
Then after I got more comfy with WoW I rolled a Druid and went Resto. My healing gear sucks, mainly because we have been raiding SSC/TK, and just missed the KZ farming for the most part with my Druid. I do have a few KZ items, and one ZA item tho XD.
Anyway, both can DPS. Both can tank. Pallies seem to be really needed for a lot of the AoE pulls KZ on up. Before we got a pally tank... dragonkin boss in ZA was such a PITA, after... 1 shot everytime (unless we just get plain bad luck).
As above poster said, check out the classes, and make your own choice tho... It's the class that you'll want to play up to 70 you should question, not what is better.