No it won't, the current gen is only half way through it's life.
Maybe if you believe what Sony and MS are telling you. If you pay attention to what they're
doing (MS is already distributing their CPU chipsets in devkits and Sony is already developing the next PlayStation with a new AMD GPU), you can see that things are a little further along than that. 360 and PS3 have been out for 6+ and 5+ years, respectively. If you really think it's going to be 2016-17 when the next gen comes out, I've got some real estate to sell you...
Really, Sony and Microsoft can't afford to wait. If they give WiiU a 2 year head start, there is going to be a lot of ground to make up. Not to mention that the GPUs of the two are becoming rapidly dated. 4-5 years from now they'll be downright antiquated.
And when a company says they want their console to have a lifespan of X years, that doesn't mean they won't release another console until that time. PS2 is a prime example of this; only in the past couple years did game development for it effectively cease, but PS3 has been out since 2006. Sony will tell you PS2 has had a lifespan of over 10 years. There can and will be overlap.
I'd bet a fair sum we'll see announcements for XBOX 720 (or whatever it'll be called) and PS4 in 2013 with a release in late 2014. That'll give PS3/360 and 8/9 year runs as flagship consoles, which is very healthy, among the longest ever.
Now if you look at the timetables for BGS-developed titles (Oblivion, Fallout 3, Skyrim at about 30-36 months average) and project a new AAA title accordingly, that would put the a potential FO4 release in the same Q3/4 2014 window.
One could think that FO4 might be a swan song release for the current gen, but if devkits are already being assembled/distributed, it would make more sense as a big splash launch release.