20% has been standard for at least the past 5 years, Frank. Some folks sadly insist on sticking to the old standard. In 2011, $2.13 an hour is really not a living wage.
And most restaurants, sadly, stick to paying the old standard for a wage too.
The cost of meals has gone up as well, the prices keeping pace with or outpacing wage increases elsewhere. If you stay with the standard 15% you are still increasing the "wage" from 5 (or 20) years ago.
I also find it annoying that a lot of places suggest the tip based on final bill, not pretax. So I really don't think the restaurant industry has a place telling me I now have to tip 20% or I am sending servers to the poor house.