A lot of people have been saying, "Now that all three 'next-gen' consoles are out, can we please stop saying 'next-gen' in reference to the games?" My answer to that would be that while we now have the consoles, we don't necessarily have the games yet.
All consoles have three points where they could be considered next-gen milestones. The first milestone is when we see graphics that just weren't capable under the previous generation. The second milestone is when the extra power provides a gameplay experience that was simply impossible with the previous generation. Finally, there is the point where next-gen actually arrives, when the gameplay and the graphics meld in a single title. Let's look back at the Super Nintendo and use it as a basis for comparison.
At launch, there was PilotWings, which graphically was doing something that simply could not be done with the previous generation because of the new graphics chip in the SNES.
A short time later, there was Super Castlevania IV, which while it may have had a very odd visual style compared to the rest of the series, used the power of the console to allow new gameplay challenges (navigating a level that rotated), new player capabilities (diagonal attacks, swinging, etc.), and enemies that would have been impossible on previous platforms (an enemy growing as it was attacked, restricting the area available for the player to move around). However, there were many locations in the game where graphics weren't all they could be.
About two years later, we got StarFox. One of the first console games to provide true 3D graphics, StarFox used the power of the console to open entirely new avenues of gameplay: wingman protection missions, multiple routes through the game via difficulty level selection, ship damage that affected navigation and combat, a mixture of rail-based and free-roaming combat, and more.
So the question you need to ask yourself when deciding whether or not next-gen has arrived is which is important to you: the graphics, the gameplay or the fusion of the two. For me, Super Castlevania IV was the point where next-gen arrived for that generation because it let me do things that I wanted to do in previous games in the series, and the power of the platform let the developers do it.
What will it take for next-gen to arrive for you?