I really think that if Allen comes in we should let Spearing and Adam go.
Gerrard, Lucas, Henderson, Aquilani, Allen, Shelvey is enough for our midfield 3, and if Dempsey comes he can play in the most advanced of the 3 roles. If anything, we need another competent defensive midfielder, whereas I see Spearing as a Henderson light - he has a good work rate and can pass the ball about, but that's about it.
Like the guy, but think he should move to get regular first team football at a lower level and develop his game. I suspect he will be sat watching Allen, Lucas, Gerrard and Henderson play regularly, Aquilani if he stays, and Shelvey.