There’s an interesting article online about the networks’ attempt to combat the recession. It suggests cutting the number of episodes per season, following the British model for scripted fare.
The writer is referring more to the British scripted dramas rather than comedies. In England, comedies are (usually) written by the creator(s). As a result, a British comedy usually has only six episodes per season. This both helps keep costs down and presents no haggling over ownership rights since there are fewer writers.