It was supposed to be the iPad killer and in many ways it was. Well, it didn’t kill the iPad, but it took a small chunk out of its dominance during the Christmas rush of 2011. Apple may want to return the favor if rumors are true about a 7-inch iPad with retina display. Rumors are rumors but when Apple is involved, they tend to make news. If it’s true in whole or in part (and there’s no reason why Apple wouldn’t want to attack the market before next Christmas) then it could mean that the one place where Android devices (and particularly the Amazon Kindle Fire) still has playing room may be torn down by the Apple…