I agree with the fact that GTA hasn't done much to advance the series, but I disagree with the notion that they're recycling tired gameplay because they know people will buy it anyway. I just think they've found a winning formula and don't want to tarnish it by trying to modify it. I think it'd be cool for Rockstar to explore other avenues with the series, but I think that would be best left for spinoffs and side-games.
That being said, I would never pay 60 dollars for GTA V. And in that sense, I do agree with the dissenters, because I already know what to expect from the game before it's even released. But I don't think that's a bad thing, for the people that are loyal fans of the series. And really, the same could be said of any major series. For instance, I'm gladly going to drop 60 on Skyrim in a week's time. But there aren't many people I know that are going to do the same, because they already have preconceived notions about the Elder Scrolls series and its style of gameplay, and if they only moderately enjoyed Oblivion, the cost won't be worth it to them.
For established genres like this, it mostly boils down to fan service. People who dislike GTA may not enjoy the static game mechanics, but that doesn't mean it's not the best course of action for the series. Rockstar would likely rather appeal to the handful of people who WILL spend top dollar on the title, than risk trying to pull in a new demographic who might do the same.
I didn't mean for this post to be this long but I suppose it happened anyway. Regardless, the game looks pretty cool.