Why would anyone with a console and a slight interest in games buy any game other than GTA 5? It sounds like GTA 5 will be one of the most content rich titles available on console, maybe even the most content rich (After Skyrim, I assume.). It has tons of freedom, so you're not forced down a narrative. The content to price ratio will most likely be awesome.
In regards to "next gen" comments -- why? The developers have basically mastered the console architecture now. These games will be the best of the best on the console, while the newest games on the upcoming consoles will surely not be as great as they can be, and have typical "next gen console" issues. Why would you want the developers to put these titles on a new console, a console they've barely worked on? Increased asset resolution and all related costs just means that the games will be smaller and emptier. Do graphics really matter that much to you? Next gen consoles are just as likely to innovate gameplay-wise as current gen consoles are. Actually, current gen consoles are far more likely to innovate with gameplay.
Speaking of which, does anyone know if the entire ocean floor will be explorable, or will it be limited to a certain area around the main island(s)? Like if you swim out 200 meters you'd hit an invisible wall. I assume the game will have boats, so if the entire ocean floor isn't explorable, it'd be kind of awkward -- like if you jump off a boat 200 meters out, you'd be able to swim around, but if you jump off the boat 400 meters out, you just respawn in the boat/at the shore?