So the ps4 just passed the Wii U at around 3.2m units sold.  What consoles are next in line?  

I looked it up and found this.  

Genesis: 3.58m

Gamecube: 4.04m

Vita: 5.2m

N64: 5.5M

Saturn: 5.8m

PS3: 10.5m

Wii 12.7m

So after just beating the Wii U,  in the next few months it will beat the Genesis and the Gamecube. Then next year it will beat the N64 and Saturn by the end of the year or soon after.  Next up is likely to be the vita which will be over 6m.

After that it's uncertain times.  The ps3 is next which right now it's on track to match.  Will be interesting to see if it catches it. 

The Vita...?

You can literally see what consoles are in line on this site. It will beat the Vita and that's it.

Failure

I would say goal would be to match PS3. Sort of crazy to think of a region where that is a long shot for the PS4.

Holding off the NX which will be a lot harder than the Wii U

Beating the X1!

Vita... And that's pretty much it. No way in hell is it even coming remotely close to the 3DS.

1) Vita

2) PS3

3) Wii

And then later on we will see if the NX can beat the PS4. 

wow it did? Didnt know yet