NVIDIA predicts that two years from now, mobile SoCs like the company's Tegra solution will be more powerful than the Xbox 360 console.
Nvidia provided the slide shown below to Anandtech that highlights how far graphics performance has come since 2001 and where they expect it will go by 2014. The solid lines in the chart are estimated performance while the dotted lines represent trends.
The console line starts with the original Xbox in 2001 and continues with the Xbox 360 released in 2005. Mobile GPU performance starts in 2007 with the first iPhone and moves through Tegra 2 and into existing Tegra 3 parts. We assume that the PC line follows various Nvidia GPUs throughout the years.