I doubt there would even be that many ps4's and XB1's manufactured in 2013

Yes, x1 and ps4 can easily outsell what the wii did at launch. Nintendo was coming off a 22mil console and didnt expect to sell that x5

Both consoles combined? totally possible.
Either of them? holiday 2014 for sure.

Lol, doesn't take much faith with numbers like Donkey Kong's 5m, Wii Party's 7m, Mario & Sonic's 8m, Super Mario 3D Land's 8m+, Super Smash Bros' 10m, Wii Fit's 20m, and Mario Kart's 34m. Compared to what? Killzone's 2.9m? Infamous' 2.6m? Lol, ok. You could've maybe argued Kinect's 20m if the thing wasn't $500 plus subscription. "Hardcore gamers" have never and will never influence how well a system will sell. Get ready for a shit storm come the end of Janaury than all next gen consoles are completely out of the womb and have to fair for themselves without preorders or black friday to protect them.

Ever notice how not a single one of the major video game news outlets has reported the PS4 10 million or the Xbox One 7/6.2 million shipment stories?

I'll just let you guys think on that for a moment.

I am not forgetting it, but even Wii would not have managed 6.5 million in it's first two months with adequate supply, and it has the price advantage over PS4/XB1 (which is important for the parents buying kids demographic at Christmas)

However, demand for the Wii aside, Sony and/or Microsoft will be worried about overproducing (particularly Sony given what happened with the PS3)... If Sony thinks the demand for PS4 is similar to that of the Wii, they will probably be wanting to have more like 4-5 million units for 2013.... to surpass the WiiU they would need over 7 million (bare in mind Sony was burned with the PS3 when they manufactured 5/6 million by March 2007)

Then there can be manufacturing issues that limit what Sony/MS will even be able to produce within the timescale... probably not anything like Nintendo because they are much bigger companies, but weren't both X360 and PS3 supply contrained at launch (for a few months for X360, and PS3 was delayed in Europe because of them) and I doubt either of them had half the number of units shipped in time to make 6.5 million sales possible. I suspect both will have learned a little from past mistakes (e.g Cell chip being complicated to produce) but consoles still have custom chips and new and unusual electronics that aren't already manufactured in bulk like ARM chips for smartphones.

I can't say I have been keeping up with the news much but I think best case scenario for PS4 (assuming there is Wii like demand) would be 4.5 million units in 2013, and maybe 3 million for XB1 (higher price plus more unusual parts to manufacture with Kinect and the supposed custom chip MS designed... oh, and Japan)

That's 7.5 million for the both of them together and I think I am being generous with those figures.... after all that has the XB1 matching the Wii, AND the PS3 doing 50% better than the Wii did.

No, that was only leo-J. Others know this won't ever happen.

PS2 launch came off a (at the time) 80 million strong console and the Wii smashed it's records (admitedly staggered launch is clouding any real comparison there)

PS3 launch though came off a >100 million strong console and Sony still didn't expect 7 million sales by the end of 2006 (based on their fiscal estimates they were intending to manufacture (not ship, nor sell) 6 million by April 2007)

Yes, but it wasn't fast enough to do that in 2006:

http://www.vgchartz.com/yearly/2006/Global/

So I think PS4 and X1 will also not be able to do it.

EDIT: Deleted