2.5:1 in 2013
2:1 lifetime.

Probably the same ratio that they are shipped. So Sony should definitely outsell Microsoft by a large amount, but that just depends on how many they ship.

(This means I expect both consoles to pretty much sell out.)

only because of the price
xbox one is now selling better after the DRM reversal so expect more pre-orders from xbox one

Only?  No it isn't.  There are dozens of reasons but they have already been stated a just as many times in this thread.

Also the reason doesn't matter.  

2:1 sounds just right.

This seems about right considering all the negative xbone press. it could even be up to 4-6:1 with all the ps4 preorders and positive hype.

I agree with the op.

It all depends, but yeah, it's very likely, in terms of LT i think ps4 will sell more then x1 and wii u combined.

The rumour is that MS is having problems with yelds and won't have the desired amount of X1s at launch. The rumour says that Sony started the production earlier. Some news were around saying that Gamestop stores are receiving less preorders of the One than the PS4 (talking about maximum number of preorder they can sell allowed by the manufacturer, not actual preorder sales to consumers. So the 2:1 number could be true.

Of course, we will only know for sure which console is winning in 2014, when both won't be supply-constrained anymore.

2:3 ratio is more likely I think. I think it really gets down to how many units each company can produce at this point. No matter how many they manage to ship in 2013, they will likely sell out of their stock. At this point in time, it looks like Sony will be able to produce more units than MS in 2013.