I have experienced this problem tonight.
I dashboarded after playing Final Fantasy XIII-2 and went to restart the game and my screen got stuck on the Square Enix loading screen.
I have cleared my cache, uninstalled game etc and it still does the same thing. My disc is clean and I have also tried a few other games such as FIFA 13 to make sure it is not my disc.
FIFA 13 loads up but only makes it to the first screen. Also on all discs in the home menu it tells me what game it is so at least it is reading the disc and knows what game it is.
I have tried all the troubleshooting methods before posting this and they have not fixed the problem.
I must say though my xbox is omitting a lot of heat from the fan area so whether the xbox is overheating I would say is a possibility. I have a xbox 360 slim version and have had it for two and a half years.