Sony Confirmed: PS Vita can be used as PS3 controller/RemotePlay/Other Info

It's not a cartridge. It's more of a memory card. Nintendo uses cartridges and Sony doesn't. There's not that big of a difference other than size...and the fact that Vita is better than the 3DS. /subjective

As for casual, that basically means mainstream games. Just about every single shooter out there is a casual game(anyone deny it and I will kick you in the face). Generally any game that's "easy" can be considered a casual game and anything abstract or otherwise odd or lacking generalized main characters(SPACE MARINES EVERYWHERE) are not casual. ...I'm not very good at defining this stuff.

In any case. I'm not surprised that the Vita can be used this way. I seriously thought this had been confirmed ages ago.