According to a post on his myspace page, Diego Sanchez intends to fight at 155lbs in his next bout although there is no bout to speak of:
So my account got hacked and it took a while to get it fixed, but I'm back. I'm training hard and will be dropping down to fight at 155. I will keep you all posted on the info of the fight! But I promise you all that I will do my best to win.
Kind of odd to see Sanchez move to lightweight considering the clusterf*** of talented fighters sitting at the top of the ladder already with no champion to fight against as BJ Penn will be challenging Georges St. Pierre for the welterweight title in January.