This topic has come up on IRC a couple of times, and since many people here are working on games it pretty much deserves it's own forum discussion ;)
In my opinion, most questionable is the term "next gen", which is used way too often. The most notable change in games since the arcade classics is the integration of collision/physics engines, rather than using rough approximations. Sure, they set the standards for graphics a little higher every year (and the HW requirements), but nothing really ground-breaking has happened to gameplay or A.I. in the past year on the PC. Unreal Tournament is imho a good example, I loved the initial version of that game because it came with the 'Assault' game mode where you had deeper objectives than just 'kill enemies, don't kill teammates', but it's 2003, 2004 and Unreal Tournament 3 sequels didn't really tempt me to play it again at all, not even with a shiny 'now with vehicles!' sticker put on it.
From a marketing standpoint their decisions surely are viable (never change a successful concept), but please don't name graphics updates 'next gen' :P
Games like Starcraft, Diablo, Counter-Strike, Battlefield and World of Warcraft have heavily outdated presentation, but still have millions of players every day. Ask yourself, why is that?
According to http://www.vancouver.wsu.edu/fac/peabody/game-book/Coverpage.html the primary motivation to play games is to learn. Secondary motivations are fantasy/exploration, nose-thumbing, proving oneself, social lubrication, exercise, and need for acknowledgment. (mind he's not writing about videogames specifically and it's probably more complicated than just those few motivations)
All the games listed above fulfill these basic needs though (if you can live with exercise==moving the mouse), and what makes them outstanding from the competition is that they are easy to get into, but difficult to master - providing a challenge even for experienced players. This is also true for many arcade games: the controls are very simple, but the further you get in the game the harder it gets.
Imho this is often overlooked in games, their approach feels more like creating a graphic demo first and then attempting to tweak it to become a game.