1-30 Ranger (get 4 in Ranger ASAP for HoT, use only Boar pet) - doesn't matter what other soul you pick
31+ go the standard Sin/RS/BD route
Sin/RS/BD just got a whole lot stronger in 1.5 due to the changes to Twin Strike (now Quad Strike).
These are not PvP specs.
Oh, and you're wrong if you think the grass is greener (it's a tradeoff). Warrior vs. rogue (even after 1.5) is really just a playstyle difference.