I just wanted to chime that I understand this service will not work for all games:

Games the multiplayer will work with
1.) Any games that support split-screen: Mechs, Racing, FPS, MOBA
2.) Platformers (same screen)
3.) Beatem-Up/Hack-n-Slash
4.) Schmups
5.) Top down action games
6.) Party Games
7.) Music Games
8.) Sports
9.) Puzzle games
10.) Trivia games

Games this tech will more than likely not work for:
1.) MMO
2.) Games that don't support split screen that do not share the same screen: Destiny, Driveclub (rumor is it's being worked on), possibly COD

To be fair, I expect more games to support split screen after the technology is available. In the meantime, some genre's will get the short end of the stick for 2 player support; however, those titles generally have online multiplayer as it is.

I'm not entirely sure you've understood what this is. It should work with every sort of game.

1) Play games together even if your friend doesn't own the game.
2) Quickly demo a game from a friend. Good games will sell more. Bad games will die quicker.
3) More reasons for friends to all get PS4 instead of something else.
4) Profit.

with the way sony is going with gaikai,.. i wouldn't be surprised if shareplay supported pc at some point down the line.   probably a while down the line (like after gaikai supports pc) but sony seems exceedingly open lately.

It is by far the most interesting feature any new console has. Could be big.

the tech will work in options 1 (broadcast your game to a friend) and 2 (let your friend play,. sony is marketing this as a way to have a friend help you through a hard section or trophy) for any game.   option 3 (virtual couch coop) will only be availible for games that support couch coop.   ..and your right, certain genres of games lend themselve to couch coop moreso than others.

This is really game changing and I knew from when this was announced at reveal. Plus mentioning the couch coop. This is gonna be really sweet. I'm already talking with my friend about couch coop for RE Revelation 2.

Reread it.  I fully understand the technology...

Basically FPS that don't have split screen will not have 2 player support using this feature.  MMO's won't have two player support because you need two accounts at one time.  All games will work with the other support.

I think this could be fantastic but let's wait and see how it actually ends working.

A YouTube vid just came out demonstrating SharePlay. Looks really good.

Link: http://www.youtube.com/watch?v=aze6aI3lQOo