Which console will finish first, I don't know. Frankly i think that depends on a number of factors, price point, marketing, software lineup and least importantly relative power of the machine. This gen will also see at least one new entrant of significance with the steambox. Splintering things further. The pace of advancement in the low powered mobile devices is considerable, look at the prototype nvidia SoC slated for mid gen. Very impressive.
http://regmedia.co.uk/2013/03/19/tegra_roadmap.jpg
One thing I think is certain is that the overall market will shrink considerably. A bare minimum of a 40% drop is likely overall due to competition from other games markets like tablets and smart phones.
http://www.asymco.com/wp-content/uploads/2012/01/Screen-Shot-2012-01-15-at-1-15-8.45.58-PM.png
This gen is also in the middle of an economic malaise following the "great recession" with governments lining up
for austerity measures that will ensure a very slow return to healthy growth. Expensive consumer products like consoles that cost three to six hundred dollars will appeal to a smaller market than last gen. The core gamer market is suffering most of all (see this economist article bellow):
http://www.economist.com/news/leaders/21576663-number-young-people-out-work-globally-nearly-big-population-united
Given all of that I think that the looser in the console next gen will be the console that is the most expensive, has the most expensive games, and focuses on the core gamer market. We will see in 4-5 years.







