Tyler Cowen offers the most important lesson from BloggingChefs: Marginal Revolution: Strange Bloggingheads episodes.
If there is one lesson, it is taken from the cooking of Megan: for most of you frozen cherries will, for cooking, be tastier than non-frozen cherries which in fact are not so fresh at all.
This is actually a very important lesson. Unless you are shopping at farmstands, when it comes to berries, cherries, or peaches, buy frozen for cooking. The difference in texture will not matter, and the difference in flavor is profound. Frozen fruit is picked ripe and flash frozen near the farm, whereas "fresh" fruit is picked while green (the better to survive transnational shipping) and then ripened through a combination of time and chemical assistance. The result, as you've probably noticed, is thoroughly unsatisfying. This is also why you should use canned tomatoes for your soups and sauces in the winter; indeed, any frozen vegetable will make better soup than fresh unless it is in season.
The biggest lesson I took away from this year's BloggingChefs was: don't rewrite your menu from scratch at 10 am the day of the cookoff.