You can take the serious approach (mentioning reasonable actions that the companies could take) or a more tongue in cheek approach with suggestions that may lie in the improbable, to answer:

What could Microsoft do with Xbone and Nintendo with the Wii U to help pick up better sales with their consoles and make some sort of comeback like the one Sony did with PS3 that helped it pick up momentum and prevent ending on third place in sales?

Or do you think the cause is lost for them?

The Wii U can't. Nintendo's only remaining card to play is the NX... MS is spread too thin. Since Xbox One consoles do run Windows 10, MS can always use their last resort and enable cross compatibility with Windows 10 software. Sales might skyrocket, since people will no longer see the Xbox One as a console, but as a console, cable box, PC, home theater all in one box. Since a lot more people buy PCs and the Xbox One is not as weak as some think (it's a mid tier non gaming PC), the price and form factor might make it very easy to sell, especially if they enable the desktop for keyboard and mouse users.

Sony never really left, even their worst selling home console reached 80m and it still has better legs than the 360.

With the WiiU and XBone, there's really nothing Nintendo and MS can do. The WiiU is dead without solution, and the XBone is too similar to the PS4 minus power and japanese support to compete without big money losses. The NX will have to mix the handheld and home console audience to double Nintendo's software output, keep and reward those 3rd party companies that still work on handhelds and create an userbase big enough to attract the western publishers and other multiplat makers. Microsoft could expand the XBox services through consoles and PCs. They could create a Steam-like digital service and create the Steambox Valve never could.

bundle a free 2 year MR Skin subscription with every console sold.

megaton sales right there.

MS just needs to keep doing what they have been doing, with their disaster launch with DRM etc.. will haunt them all of this GEN. They need to just keep it clean and bring the games. People will respond to that. Continuing to bring AAA games and content will bring them back. They have great sales but the Xbox Launch is what really harmed them. They need to make sure from now on they are the console that stays away from anything DRM and let gamers make the choice upon the games they want to buy, either digital or Hard copy.

They need to put all their cards down, Bring all the niche games people have been wanting, to Conker, another Alan Wake, Banjo Kazooie, Phantom Dust etc... Along with regular Triple A titles. Find some games that need some backing and keep exclusive rights to do so. For instance, Ninja Gaiden, however go back to their roots, like the first game. Xbox needs another hack and slash game. What about buying the rights to Darksiders but make the game include Pagon gods etc.. The game could be picked up for cheap and used to bring in a niche crowd, this may be going out on a limb but I think this Genre has been ignored.

Personally I think they have done a great job with Phil at the wheel, with out him we would be way worse off, not much they can do but to try to stay profitable and bring the games. This will set them up for next gen. They also must beat Ps4 to the punch with Price cuts. We need a permanent price cut next year and bring down the cost of the Elite bundle, I want a solid state drive but am not willing to pay $500 for it even with a elite controller, take the controller out and lower the cost so I can have the solid state drive for cheaper.

MS need to setup or buy jp devs.

Not much honestly. Just ride the gen out and hope for better results next time.

Microsoft could buy Valve and bring Half-Life 3 as an exclusive. Or they could just start to throw away XBoxes dirt cheap, like 99 $ or something. Both options would be horribly expensive, but there's no way they'll make a serious comeback this gen without major losses. They should just concentrate on the next gen for gaining market share while still delivering for their fans on X1. When you know you have lost, you just need to let it go.

You know, we could come up with outrages strategies for both companies but with Micro, they never seem that outrageous considering the amount of money those guys have.

But then, I am sure the gaming division must proceed with a defined budget so there's that. Maybe the division can pitch some special ideas that cost extra money though.

Some of you seem to think MS is selling next to zero, they are making good sales, PS4 is just selling mega-tons. So anything next to that is going to look Meh but last gen Xbox One would have been seen as a very successful system. It will continue to sell well with the games coming. If  Phil didn't do what he has done, it would be damn close to what Wii U is doing sales wise, The DRM was a disaster. Really I'm not sure how the hell this got past testing stage or was really taken seriously. This should have been easily focus group tested and disapproved as fast as it was brought up. They would be neck and neck with PS4 with-out. Same with pushing Kinect, they should have seen all of this coming.