If you were planning on just waltzing into the retailer of your choice next year and buying Infamous: Second Son for the PlayStation 4 off the shelf on a whim, then Sony wants you to know that you're missing out on some exclusive content.  Like every other major release these days, Second Son is getting the Limited and Collector Edition treatment, and while the latter offering is overpriced and contains a handful of junk you'll most likely never use, need, or want (premium beanie replica!), the Limited Edition intrigues me.  Preorder the game (existing preorders included) and you'll get the free Cole's Legacy DLC expansion that will not be sold separately later.  Here's the PlayStation Blog with the information:

But what’s this Cole’s Legacy DLC we mentioned? For one, it won’t be available for purchase when Infamous: Second Son launches. It’s only available through these offers here. It’s additional downloadable content you’ll be able to play that uncovers what happened between the devastating events of Infamous 2 and Infamous: Second Son.

Cole MacGrath’s actions in New Marias set in motion a chain of events leading to the now forceful occupation of Seattle by the oppressive Department of Unified Protection. Cole’s Legacy bridges this gap in time with a series of missions Delsin Rowe must complete that reveal unique insights into how the world of Infamous: Second Son came to be.

More playable content?  I'm in for that.  My cynical side says that Sony will eventually sell this DLC separately long after most people still care about it, but ever since Sega burned me by not selling its Sonic Generations PS3 DLC separately outside of preorders, I don't take chances on missing out on content I want to play.  I can be swayed to preorder Infamous: Second Son if there's extra missions available for it.  Maybe that makes me part of the problem, but the Limited Edition is a better deal than the Collector Edition's vest pins and patch.  I love a good tchotchke as much as the next person, but there's a line between nostalgic neatness and useless marketing.