I estimate that xbox will sell 5 billion consoles, and PS4 maybe about 100k.

It's a good question no one thought PS3 would ever overtake the XBOX 360 early on so the future is never certain. In my opinion it will be very hard for XBOX to PS4 in life time sales however. XBOX will never gain any traction in Japan so they start with a big disadvantage right out of the starting gate.

Europe has traditionally been Sony's market too so I'm not sure what Microsoft would have to do in order to win over that audience. A free FIFA game with preorders won't do it, they'd have to secure FIFA as an exclusive or something huge like that to make it happen.

XBOX still has a shot at being better in the US market though and that made a huge difference last time around. Sony would have to get lazy though and not put out as many good exclusive games as Microsoft that appeal to American gamers.

It's hard to see a scenario were Sony doesn't at least match Microsoft's exclusives in terms of both quality and quantity. I think if I had to guess Sony will still have more quality exclusives only because of how many studios they own. Microsoft will still have the biggest selling exclusives I think like Halo, Gears, the sequel to Titan Fall (if it stays exclusive) but Sony will still have more  like Uncharted, God of War, Little Big Planet, Last of Us, Infamous, Killzone ect.

We still have no idea how many new IPs will come from either PS4 though or Microsoft which is the major wildcard. It is Sony's battle to lose but they can't take their foot of the gas and and be slow with their big game releases or they are giving Microsoft a window of opportunity.

If Sony can at least stay even (or win) in the US market it's over, if they don't it could be close again...

12 from Sony in the first year with 8 from MS according to Sony's E3 conference and MS' reveal respectively.

M$ has a very long road to go down with the pricing strategy that they have chosen. The only way to overcome that is if they produce some type of Fad like game for the Kinect that makes people feel that they have to have it. Sony will probably sell 20% more units than M$ otherwise.

I said NO but there's a good chance that it will on release week.

If? Halo 5 is "confirmed" for 2014, is it not?

I don't see it surpassing the PS4 anytime soon but anything can happen in the future.

Microsoft showed earlier in this gen that they are not shy with going after exclusive games and content and have really gained a lot from previously unimportant things like timed-exclusivity etc. This plus the more level playing field with XBLiveGold/PS+ both needed for online play and Microsoft's increased 1st/2nd Party precense (or at least seemingly to me, admittedly I haven't followed Microsoft nearly as closely as Nintendo then Sony in video games in the past).

With the $100 difference not in their favor and the opinion of most people (at least that I've read) that the PS4 is the stronger of the two consoles, they have an uphill battle: but if they make a lot of the right moves and perhaps Sony doesn't (they seem to be doing really well but they've gotten cocky, arrogant and/or complacent in the past just like any other company) I don't think you can rule out the XB1 taking the lead over PS4 in the future, whether that be temporarily at some point or eventually permanently (again it depends on the situations, which really are unclear and nearly impossible to predict reliably).

no never evar PS4 has a better shot at taking back US then this happening

Should do for 1 week, if MS Launch Shipment isn't more than Sonys North american shipment total, then there gonna get nailed, as sony will pick up thousands of extra sales from the people that wanted an Xone but just couldnt get one for xmas.

Much of that for 2013 simply depends on shipments as likely 95-100% sell of what they put out this year for both companies.

After that? Too early to tell, but I'd guess by Sony have advantage in 2014.