I don't see Clinton exciting voters on the left or in the center, she certainly doesn't do much for me.
I really like Warren's ideals, but I also liked Obama's ideals. There's a huge difference between ideal and reality though, and Obama, the President, has been a pretty big disappointment in certain areas. I think Warren would get bought out, and pushed around, just like Obama, but maybe even moreso. Warren is better for "left" politics, staying right where she is.
Basically, if the "right" doesn't win the 2016 POTUS race, I'll be incredibly surprised. We could have a new "golden era" of Republican control, which should be interesting.