I was fortunate enough to meet Elizabeth Warren when I visited harvard back in 2000-2001. She was super-friendly, obviously incredibly smart, and generally a good egg. Having said all that, however, her announcement of her plans to run for the US Senate inevitably brought to mind William F Buckley's famous quip that "I'd rather entrust the government of the United States to the first 400 people listed in the Boston telephone directory than to the faculty of Harvard University." Ditto. I'll be sending Scott Brown some more money.
Also, check out this post for links to Todd Zywicki's critique of Warren's scholarship and this post on whether Warren will be the Democrat's political savior.