Hopefully Schweitzer. He'd give a good speech.
A proven charismatic speaker with a unique style who's popular in a red state and has had a good record as governor. He's be great. If Heinrich is a good speaker, maybe he could get it too.
Absolutely not to Baldwin. She's way too liberal, plus her speaking style would not play well to a national audience. Kaine would be a Warner redux. A fairly dull and unmemorable speech. Debbie Wasserman Schultz is not particularly charismatic, plus she comes across as too liberal, overly partisan, and has a tendency to make gaffes.
I'd be okay with Warren. She's a pretty good speaker, but if we want to elevate someone for 2016, she's not an option, at least in my opinion.
What do people think of California AG Kamala Harris? She is very liberal, but if she's a good speaker, it could work out. She has a great life story to tell, plus she'd have appeal to women and minorities.