Looking at Narayana Kocherlakota's brief on "Toy Models" that Noah Smith flags, my reaction is that in macroeconomics these days, there is much too much respect for the older generation of macroeconomists. Scientific progress requires a certain level of disrespect for one's elders. I feel the needed level of disrespect for one's elders is currently lacking. Many rules were set down at the dawn of the Rational Expectations Revolution. It is time for more of those rules to be broken. You can see some of my opinions on how the old rules should be broken in my post "Defining Economics."
I understand that many young economists feel the need to get tenure before they start breaking the rules. But then it is imperative to have a plan for how to keep your determination to someday break the rules alive during the long road to tenure, so that you haven't been totally coopted by the system by the time you get tenure. My post "Breaking the Chains" also talks about this struggle to nurture the authentic scientist within during that long journey.
In the many interactions with young macroeconomists that have been generated by my sojourn in the blogosphere, I have run into the following phenomenon more than once: a yearning for a different way to do macroeconomics, coupled with a resignation because there is only one allowed way to do things. Balderdash! There are many ways to do macroeconomics. Collectively, we make up our own rules. I think macroeconomics would be better off if the rules established by a now aging group of macroeconomists were set aside for new rules made up by the younger generation of macroeconomists. Any rule that is 40 years old deserves to be isolated and examined closely to see if it still serves scientific progress in macroeconomics.
Unfortunately, many of most prestigious macroeconomists in the world have an authoritarian streak or are possessed by intolerant ideological zeal. (I mean "ideological" in a scientific sense, not a political one.) It is important to notice authoritarian streaks and intolerant ideological zeal and to be prepared to disobey when you see fit in order to further the progress of science.