Most analysts would say "the country would never elect another Bush as president." They are nuts. Bush could debate Obama in a manner that would shock not only Democrats, but moderates as well. This guy is fast on his feet, knows public policy inside and out, and is no stranger to the presidency.
As for any comparisons to his father or brother and their presidencies, the nation would get a taste of the best of both men. There would be no question about whether Jeb Bush could meet the interests of the conservative side of the GOP. The good news is that he is strong in his convictions, and he is able to articulate them in a very positive way. There would be no ability for the press to unfairly characterize him as inarticulate or not bright. They got away with it to some extent under his brother's administration -- which is pretty ironic because they drooled over interviews with him when he released his autobiography.
In the case of Jeb Bush, it is obvious you are dealing with a very smart guy who will get the best of most in any press conference or tangle with the media. It would be a blast to watch the media's frustration trying to deal with him.
The real issue is whether anyone could convince Bush to accept a nomination in 2012.