With the success story of the fastest selling console continuing today with PS4 becoming the 8th gen leader 3 months after launch, when will the milestone of 50% marketshare come to fruition? If at all. It almost looks a foregone conclusion at this stage in the game. 

I believe by January 2015, Ps4 should comfortably take at least 50% marketshare. This was such a focal point of the Wii era that ALMOST came to pass but never happened. 

It's 60% this year, so why not. But you never know :P

About Nov.

That's assuming the other consoles just keep doing what they're doing and don't make any significant changes to their momentum.

I think it will come close and perhaps possibly have it for a while but I don't think it will end up at 50% marketshare lifetime.
If the PS4 is to comfortably take 50% or more marketshare by January 2015, it will likely need to be at at least 20 million by year's end, that doesn't seem very likely at all from where I'm sitting.
It largely depends on how the others do as well though, if the Wii U remains more or less flat yoy and the One manages to barely sell above those levels; it's possible but I find it extremely unlikely.

Xbox One, Just like PS3 will come back and sell very high, They already signaled they will drop price, meaning will well see a price cut in the Fall. Most likely $100 off. This will push numbers very high for XBox One. The launch was very successful and looks like they just need the price to be right. The ones not buying in, obviously think $500 is just to much and to many it is. However $399 would be acceptable I think. So No I don't Think PS4 will get 50% market Share. It's only a matter of time before MS makes some major moves and this will stimulate sales.

After seeing what little SM3DW did I don't have very much confidence in other traditions saving WiiU (much as I actually hate to see that happen). Xbox I just don't see much changing unless they unbundle Kinect. I can see some good bundles with KZ this coming holiday and strong software in Infamous, The Order, Driveclub, and of course all the big 3rd party games as well as Plus consistently outdoing XBL offerings.

This exactly.

Microsoft has never signaled a price drop, the only thing they did is 30 bucks in the UK... Microsoft probably wont do a $100 price drop until they can manufacture the Xbox One for $100 less, or unles they drop the Kinect out of the package (which they wont). Because if they would, you'd start selling the Xbox One at a loss, which is the last thing you want to do.

I predicted roughly 45-50% market share with expectations of significant contraction in console market, particularly affecting Nintendo.

Of course things could change in coming years and we have no idea how long this generation will last, could be 5-6 years, could be 9-10 years.

That would rely upon sales of the Wii U or the XB1 to completely stagnate, which within the first two years of release for a new console would signal the death nell of a platform (like the Dreamcast).

So as much as I favor the PS brand as my go to choice for gaming, I sincerely hope not.

The only other way for this to happen is as Mummelmann previously stated, would be for SCE to sell more hardware units (20m) than they are currently capable of physically manufacturing.

Making a prediction like that (20m sales to hit that 50% marketshare), would be like Nintendo fans making Wii sales predictions that outstripped Nintendo's manufacturing capacity.