I think if they decide to sign him, it would be a loan with a view to a permanent move. The last two americans that Moyes brought in were from the developmental leagues (USL) or whatever they are called. This guy has a little more seasoning having played at the MLS and internationally.
I agree that they have plenty of holding midfielders. The fact he is there makes me think that Heitinga and probably somebody else(Pienar) are on their way out. Maybe Moyes will start to play Arteta further up and stop wasting his talent trying to turn him into Xavi.
That sounds to me like average size. I think the biggest issue is getting used to the speed of the game, but with his positioning I think he could make it. He would not be a starter but could be a squad player. What do you think of Zakuani?