There's simply no way of know how many were in the channel. It's very possible that there were none.
I disagree that that's possible! I think the channel always has some in it, on trucks on the way to stores, at distribution centers, etc. That's a worldwide distribution channel, so it will be quite extensive!
I'd say minimum 4.4 PS4's shipped, for some reason my hunch is 4.9, too bad Sony wont solve these issues for us and come clean!
At least we can always compare XBO+x360 vs PS4+PS3 going forward. PS2 is out of the picture, confirmed by Sony, so that's nice. Going forward PS3/360 will become less and less relevant and the numbers will become closer to a straight PS4/XBO number too.
Microsoft sold just 5% less home consoles worldwide (7.8/7.4) in Oct-Dec, that with no presence in Japan, not too shabby. I expect that number should turn worse as PS4 should open more of a lead on XBO (until a price cut or we'll see about Titanfall) and prior gen falls off, but still.
The fact Sony had less PS4's in the channel should manifest itself in coming quarters as a bigger PS4 edge, even than the actual end user sales gap. Ship numbers are self correcting in the long haul but can give a misleading picture on any given quarter.
Also, I've noted in the past that for whatever reason Sony tends to ship more holiday PS3's in the calender 3rd Q than MS. It held true again this year, in Jul-Sep PS3 shipped 2m and X360 only 1.1 IIRC. So even if PS3 shipped substantially less in Q4, the 6 month number is likely close to equal, as you'd expect.