Slate:

In America, bubbles form because any good business idea gets funded a dozen times over. That's the American way. Cupcakes are now showing every sign of going through the bubble cycle. The first-movers get buzz and revenues, gain critical mass, and start to expand rapidly. This inspires less-well-capitalized second- and third-movers, who believe there's room enough for them, and encourages established firms in a related industry to jump in. In New York, the Crumbs is joined by a cupcake truck, Sweet Revenge, Babycakes, and Sugar Sweet Sunshine.... Operating in what is essentially a commodity market, newcomers try to distinguish themselves by offering twists on the familiar formula. Hello Cupcake, conveniently located near Slate's D.C. office, specializes in organic, seasonal, and local ingredients. Babycakes offers vegan cupcakes. Coming soon to a precious storefront in a gentrifying neighborhood of Brooklyn: sustainable cupcakes made of flour ground from organic wheat raised in Prospect Park, served in wrappers recycled from old copies of the New York Review of Books.

I'm suspicious of the durability of the cupcake boomlet on economic grounds, too. One colleague says the cupcakes are "sort of the baked equivalent of Bush's tax cuts." Why? "Their economic rationale withstands any and all conditions. When the economy is going well, people can afford little extras like cupcakes. When the economy isn't going well, people can afford only cupcakes."