Hate to say I told you so. Just kidding, actually, I love it!
I really don't mind the delay. I just want them to make good on the idea of switching characters anytime in real time. I don't think they can do this but would love to see R* try. I think what will happen is when on certain missions you will be able to switch between characters in real time, but outside of that I can imagine when you load up the game you will choose who you want to play as...and outside of certain missions you will need to load the other characters from the pause menu.
I just don't see Rockstar pulling off seemless character changing anytime in real time, but oh how awesome that would be. This game is going to kick so much ass I think it will define this generation--on a side note--I think Bioshock Infinite will do the same and with titles that good (hopefully Beyond:Two Souls and The Last of Us as well) who needs new consoles??!!
*Edit* And to add to that, If Microsoft or Sony does launch this year, launching just a couple months after this enormous game could be a real issue--many will still be scrambling to put this game on their xmas list while others, such as a couple of friends of mine I'm sure of which aren't the only ones, will finally be diving into this generation just for GTA V.