Mary Z. Connaughton, who ran for Auditor and lost to her unqualified opponent on the strength of zombie votes despite receiving the endorsement of literally every newspaper in the state (sort of like Tisei, actually). She's also our own Nathan's aunt She's probably too socially conservative however.
Cousin, actually. (Technically a cousin's sister-in-law, but cousins by marriage count in my family.)
Mary's great and a lot of fun, and she's probably the only Republican I'd vote for for Governor, out of family loyalty even though we really don't agree on the issues, but she's far from one of the likelier candidates. Particularly after Romney lost last year she's seemed pretty disillusioned--she was very reluctant to discuss anything political at Thanksgiving, which is unusual for her and wasn't the case after her own loss--and although other members of our extended families know her a lot better than I do I don't think she's inclined to run for office again any time soon.
She's within her rights to be disillusioned. It's blatantly obvious that she
should be State Auditor right now and would be if even slightly more voters had actually paid attention to the race beyond superficialities--like Tisei, as you said.
I'm going to go ahead and agree with most of the previous posters that Baker's a lot likelier to run than Brown is.