Obviously not substantive pre-order bonuses, but nice incentive nonetheless. (dualshockers.com)
Fisher - Price Kick and Play Piano Gym - offers variable toy placement AND nice incentive for baby to stretch and kick those legs Tiny Love Move and Play Playmat from Amazon -LCB- affiliate -RCB-- the whole frame shifts side to side, perfect for head turning, sidelying and Tummy Time (candokiddo.com)
Also Amazon has included a very nice incentive to use their store: a different free paid app everyday! (androidthoughts.com)