In a closed thread posted late yesterday evening, Bliz Blue Tyren states that not only will certain Season 3 Arena pieces require a Personal Rating, but they will now also require a Team Rating as well. He goes on to say that while the in-game mechanic will be changed during today's maintenance, it will not display properly until an upcoming patch is applied.
So how does this short-notice adjustment to the rating system affect Arena players and teams? With this change, Blizzard is likely trying to curb a method of artificially inflating one's personal rating, where players would engage only in "easy" games around the 1500 bracket. These players would create a team consisting of mains and alts, winning with their mains and losing on purpose with their alts, to keep their team in a mid-level bracket. This would allow them to continuously play against low-to-mid-level teams while eventually seeing their Personal Ratings go through the roof. It was an ingenious work-around to the Personal Rating requirement, but B.S. none-the-less. Blizzard recognized this and acted accordingly.
No system is foolproof, but it's good to see Blizzard trying to make theirs work as best they can. Now, if only they gave other matters this kind of attention.