Also, it sounds like Katy never had a direct problem with Taylor. Katy getting her dancers back was strictly business, and from the sounds of it her dancers were more than willing to come back to Katy, they weren't forced in any way.
This is something between Taylor Swift and Katy's dancers (not Katy directly), which Taylor has made into something between herself and Katy Perry, most likely due to the John Mayer situation, in order to gain publicity surrounding her album. I like Taylor, but I'm not a fan of her actions surrounding this situation.