Apolloa has pretty much hit the nail on the head about patenting.
A patent does not allow the owner to do something, it just provides a tool to prevent other people from doing it.
I couldn't be bothered to read the claims of the patent application of interest but from the posts above the crux of the issue is linking a game to a machine so it can't be used on another machine by internet based recordal of the association. This is already pretty much being done by MS - Arcade games can't be used on other xbox360's now can they?
I'm a patent attorney (for my sins) and big companies like Sony, will file patents on every idea they come up with, whether they think it useful to them or not. Basically the big companies do this to prevent other companies from getting close to technology they themselves are working on, or just to hack their competitors off. Say this Sony patent grants, it may be MS are infringing it with the arcade in its current form Sony will sue, or maybe Ninty will infringe based on their equivalent of the arcade. I'm sure MS have similar patents which they'll wave at sony and Ninty, and Ninty will do the same.
And so the patent world goes round, paying my wage (huzzah!)
Patents, particularly in the high tech field are usually so far out of date by the time they are granted it is unbelievable, fthey are always filed to actually prevent competitors doing stuff.
The fact Sony have filed for this patent may not even mean they prosecute it to a granted patent, it may just stick around as an application - but becaus eit has been published - it stuffs up other people applying for a patent on the same or similar technology.
patenting strategy is highly comples, which is why people like me exist. I have clients that file on everything they do just to annoy their biggest rival, others file on just the tecnhnology they are actually interested in commercialising. The bigger the company, the bigger the patent budget (this can be millions per yr) - the more patents they file - most of which the technology from never even make sit into a product.
So until Sony say that DRM and one disc one machine is inherent in the ps3, then this is all speculation.