I did a whole theorycrafting workup in MS Excel and a post (somewhere here on the forums) about ToW. The short story is:

* Nature's Swiftness, both before and after the EM+NS nerfs, is a very, very, very important skill for the 5v5 arena scene.
* Totem of Wrath is not awful in PvP, it DOES provide some extra DPS and longevity, the "resilience makes ToW useless" argument is largely invalid. NS wins for a variety of reasons, but not because ToW can't overcome resilience's benefits.
* Stacked ToWs are absolutely uber in PvE for both damage and longevity.

I think what remains to be seen is how competitive a ToW build can be in 5v5 for someone who wants to not respec back and forth for arenas. It's not going to be dismal, but it certainly won't match the capability of the 40/0/21 NS build.