It's also possible that with GB getting pretty solid reviews (despite recent PF issues), The Hobbit now shipping, a third JJP expected to be announced before year's end and too top it all off TBL now shipping, a chunk of the market is holding their money to determine which one of these fun machines they'll buy. I forgot about Heighway Aliens, which also shouldn't be too far off (in pinball release terms) as well.
Oh and Stern AeroBatJawsStarSmith.