What a useless feature...
I mean.. first off if you want 8 controllers you need to buy 7 more, which will run you at least $420 (7 X $60), which is more than the cost of a PS3 and 84% the cost of a One console. Also, what games would use this feature? You can't use it on an FPS because unless you have a 100+" television, split screen 8 ways will be like trying to watch on an old school portable television. Same with racing, and you probably couldn't use this on a 3rd person game either, whether it be action or just the wandering type. I suppose you could put it in a platforming game a'la Rayman or NSMB if you're a real masochist. The only thing I can picture where it would be somewhat practical would be sports games, where each gamer can take control of a player. I'd have to imagine that'd get rather boring and confusing really quickly. And finally, how would this work logistically in terms of players? I don't think the majority of gaming rooms/set ups are able to accommodate 8 different players.