The DS in april 2007 with the release of pokemon sold a bit more, it was april and in march it sold 500k.
If pokemon and the 2ds can't lift 3ds sales near ds levels i think the console is going to sell,at best, half of what the ds did
Half of what the DS did is pretty much where most people have been seeing the system for a long while now. I personally expect a little over 80 mil though.
I think it would be a satisfying performance considering the mobile craze. There's a lot of room for improvement in Western territories, so I'm hoping that the 2DS and the current library will increase the 3DS baseline in the West.