We covered this a while back. ToW Theorycrafting in Arenas. I started out feeling just the same, but practical experience has proven that NS is the better choice by a long margin.

If all you were going to do was BG, PvE, and maybe just dink around in arenas, you could get away with a ToW spec. To be competitive in arena, you need NS.

The big question for me in WotLK is whether to get the last elemental talent or to get ToW + NS... I think the last talent is going to be pretty damn good, though.