2. Wii...U? Despite the one year head start, there's lots of doom and gloom surrounding the Wii's successor and many mom and pop's out there still think it's an add-on to the Wii. Doesn't mean it will flat out fail, but there's no Wii-like success here, folks.
3. Playstation brand ain't what it used to be. With three disappointing product releases in a row (four if you count "Move") in the PSP, PS3, and PSV, the dominant brand that was once the "Playstation" is no more. It's no longer synonymous with games like it used to be.
5. Price. Even if the PS4's rumored power advantage comes to fruition, that means Durango should have the price advantage throughout the gen and the "most powerful" console has rarely ever been the most successful financially. (see Xbox, Dreamcast, PS4, PSP, etc.)
8. Focus. Microsoft's game division can put 99% of their focus on Durango (some probably split to Kinect 2.0) whereas Sony and Nintendo have to dedicate hefty resources to their handhelds. That's valuable development time/talent that is not available on this front of the "war"
9. Abandoned Ship. Microsoft abandoned the 360 much earlier than Sony has done with the PS3 and that's going to become evident in the first year of both systems. And in this biz, the years one and two are everything. Many of Sony's teams are still working to release AAA games on the PS3 this year before shifting focus while practically all of Microsoft's teams have been Durango-focused for quite some time now.
10. Development Kits. Not only will Microsoft's own teams and partners have more polished products out earlier in Durango's life than they did with the 360 (which were all basically up-ressed ports), but more 3rd parties will too because more Durango kits are apparently out in the wild and were out earlier (as per rumors).