The Cavalier spot has been taken by its replacement, the Chevy Cobalt, and other similar vehicles like the Honda Civic. The Ford Fusion, one of the Taurus' replacements (the other is the Five Hundred, classified as a large or full-sized sedan) has taken its former spot and is joined by the Chevrolet Impala; Toyota Camry; and others.
Other new segment standards, such as for SUVs and minivans, can be found at the link. What is interesting is that cost of ownership, from gas prices, finance charges, and other costs, have actually dropped from 2005 to 2006.
[Source: AAA via Chicago Tribune]