Jake Shields will be debuting at the 170lbs weight division in the UFC. After careful consideration and consulting with UFC representatives it was determined Jake would be finally going back to his original fighting weight.
Jake's opponent is one of the UFC's top contenders and will be announced shortly.
Shields had moved up to 185 pounds during his time with Strikeforce after having captured (and then vacating) the welterweight title. Shields then captured the middleweight crown and ruined Strikeforce's greater middleweight plans by not only beating Dan Henderson, but completely dominating him.
Shields is probably a much better fit at 170 in the UFC where he won't constantly be outsized and can ply his game effectively. He can always change weight at a later time if a renewed interest is needed. For now I'm sure the UFC will attempt to fast track him to get into a match with welterweight champion Georges St. Pierre.