Michael Cannon at Cato draws my attention to these posts by Donald Marron, a former CBO director, on the confusion surrounding recent estimates of the cost of the health reform bills. (A good place to start in fact is this earlier post by Marron, which sets out the various definitions of "cost".) The president has promised that reform will not cost more than $1 trillion over ten years. The new House bill, on the definition used up to now, breaches that limit: therefore, its proponents adopted a different definition and at least to begin with almost everybody bought it. See also this piece from the NYT's health policy blog.