Pullis eluded to it on the deadline day program on the BBC last night. He said Premier League clubs name their 25 man squads soon. When they name their 25 man squads, quite a few quality players find themselves surplus to requirements, and are loaned out to Championship clubs. He said these loan signings (Lee Hendire etc) helped Stoke gain promotion to the Premier League. From what I have heard from interviews with Flicker etc, I fully expect us to bring in 1 or 2 more loan players from Premier League Clubs.
Every season the transfer window closes and the loan window opens again 7 days later. Can loan players right up until next transfer window, but only short term loans (3 month max).