Do not fear. The generation's end is not near.
There are some people who think this will be a "standard" 5-year generation. Discounting the Wii U, which looks set to die prematurely after 4 years, the Xbox One and PS4 have a lot of years left in them. Exhibit A: Hololens and PlayStation VR Microsoft and Sony are investing a lot of time and money into these endeavors. They will not want to end the generation before these new technologies can be utilized and/or have their R&D expenses recouped We still do not have the same pace of new games that we had a generation ago this far into the generation. Devs and pubs are continuing to push the envelope, and thus it's taking longer to make new games. If Xbox 360 lasted from 2005 to 2013, we can expect Xbox One and PS4 to last at least as long (8 years). Using this logic, the earliest we should expect Xbox Two and PS5 is 2021, and by then NX will have had 5 years in the marketplace, which is "standard."