Maybe the PlayStation 4 and the Xbox 720, while still possible, might not make their way to store shelves for quite some time. It makes sense. The Xbox 360 and PlayStation 3 are network- and HD-ready. Thanks to firmware upgrades, the hardware companies can release incremental improvements to keep the consoles alive and well.
Since the future is both online and in HD, what makes an Xbox 720 and PlayStation 4 so important?
Moreover, developers face some real challenges when a new console is released. They need to learn how to exploit the hardware, which tends to lengthen development and cost the company more cash. And even though the Xbox 720 or PlayStation 4 might be able to provide Pixar-like graphics, that might be far too expensive for developers, causing most companies to balk at going that far with graphical prowess. While most gamers might want more from their consoles, sometimes, it's just not financially feasible.