Patents are funny things. Every new product needs them, but there are countless patents filed every year which never get used for anything productive.
Take Nintendo's patent for "HAND-HELD VIDEO GAME PLATFORM EMULATION", which was originally filed back in 2000 and has recently been renewed. The renewal — which took place in June 23rd this year — has caused quite a bit of chatter online, with many speculating that it could mean official Game Boy emulators are coming to smartphones. However, while we're loathe to pour scorn on such an exciting prospect, the reality is likely to be a lot more mundane.
Given that the original patent was filed in 2000 and Nintendo has done little to action it, the most probable reason for renewing it is to legally cover the company should any rival attempt to produce the same concept. As any dedicated smartphone gamer well know, this has already happened — there are numerous Game Boy emulators available on Android already, none of which have Nintendo's blessing.
It could be that Nintendo has renewed the patent in order to take legal action against the creators of these programs, or the companies which produce Android-based games consoles and use emulators to promote them. Whatever the reason, we wouldn't recommend holding your breath for Super Mario Land and Link's Awakening on your iPhone any time soon.