More information came out about PS Plus on PS4. Similar to the Xbox One change (iirc?) one 'premium' account covers the entire system. Meaning, if one person had PS Plus, every account on that system can play online. Not all free to play games require PS Plus (DC Online and Planetside 2 are two that don't, both sony games). Cross game chat doesn't (also, cross game chat is a new addition?). Media features don't; netflix, amazon, et al. (Sony needs to get HBO Go support). Automatic updates don't require PS+ anymore.
Other than usual PS+ benefits, it sounds like only online gaming is behind the paywall, and possibly cloud saving.
And they clarified that Drive Club PS+ edition. It's the "full game" limited by content, not features. Doesn't include all the cars or tracks, which can be purchased individually, or a single 'upgrade' fee. Only available for the 'first year' (end of 2013 or until November 2014?).