They have officially signed with the Denver Broncos. Terms of the deal have no yet been announced but they have indeed signed the contract and are expected to be role players in the McDaniels system.
This means that the Broncos still need a starting RB. Every top RB will be available at #12, Raji will be gone, Maualuga is falling, and another possibility, Malcolm Jenkins, could most likely be gone at #12. Look for the Broncos to go after a first round RB, most notably, Knowshon Moreno. But that's for another time.
Buckhalter has been known as a good RB around the league, his inability to stay healthy has hurt him. He's 30 years old, so he has some wear and tear, and he's probably best suited as the backup RB here, AT BEST, in Denver.
J.J. Arrington was the better signing in my opinion. A great returner, a good receiver out of the backfield and a good overall 3rd down back. He could be used as a Kevin Faulk type player in McDaniels system and expect him to be an intrical part of the team this year.