I think Mainstream AC is moving toward playing songs like those mentioned here. The ones that aren't may just be trying to fill a niche in their particular market or maybe trying to remain on the air in a market where there's another AC that is playing those songs. AC is growing up!
They are and WBEB is already a fairly aggressive mainstream ac. They are also a smart one. They wont chase songs that turn off those awesome female demos and send them to what would be hoped...98.1. It made me chuckle when I heard WLTW playing "No Scrubs". It's certainly time for that song and they are doing what they always do, but it certainly makes it much much much easier when you are the softest option on the dial, if not the oldest.