Not necessarily - she may very well be more gutless than she is ambitious. Also, she may realize that she's becoming increasingly unelectable at the national level, and probably ought to stick to her comfy blue state post.
Hillary is anything but gutless, she's the most arrogant power crazed woman since Evita Perrone. Hillary simply realized that four years was too long to run a Presidential campaign, so she has opted for the far less controversial senatorial campaign that she will once again run on a national level, claiming to be raising money and working to help the Democrats take back the Senate.
Gutless? Come on, lets not get into the sort of damned if she does and damned if she doesn't games that the leftists play with the president. If she chooses not to run, she is wisely accepting the reality of the political landscape. Why put yourself through that if you don't think you can win?
Although, now that I come to think of it, the new "smoky back rooms" are the pre-campaign financing comittments. If she's publicly saying maybe not it sounds to me like fundraising is slow and she's saying that the Soros types better get on the bandwagon or it's not going nowhere.