That said, BMW being the money grubbing company that no longer cares about protecting the M badge it has become means chances are a 2015+ M2 model will come. Car and Driver in their April 2014 issue claims the M2 is coming as a 2017 model. That seems a bit late and Car and Driver just seems to be guessing.
Here is what they had to say, "When it arrives in a couple of years, the M2 will surely be powered by BMW's potent S55 3.0 liter six. Armed with twin turbos blowing through a Valvetronic variable-intake-lift system, this engine should deliver more than 400 horsepower and rev to 7600 rpm. Transmission choices will parallel the M3/M4 options - either a six speed manual or seven-speed dual clutch auto.
Expect a carbon fiber roof and various structural reinforcements made of the woven black stuff. To hold the M2's curb weight to 3300 or so pounds, the suspension will mostly be aluminum, the oil sump will be a magnesium casting, and the brake rotors will be made of carbon-ceramic material. Aluminum body panels are a distinct possibility."
Now, that all sounds wonderful. The problem is Car and Driver is just guessing and has absolutely zero official support for their statements. That said, a 3300 pound curb weight would be lower than the M235i although not much lower than the M3/M4. With the same motor, same transmission, a lower price, and a curb weight maybe 100 pounds lighter the M3/M4 suddenly become redundant.
Another theory that is circulating is that 'supposedly' someone at BMW says the M2 is coming and will have the N55 inline-6 turbo motor that the F22 M235i already has. This would follow more closely with what BMW did with the 1M which is just take the E82 135i, change the ECU software, throw on M3 suspension bits, give it a body kit, and you are done. This is actually the most likely scenario because it would cost BMW the least amount of money and BMW already showed with the 1M they will will gladly market an M car that does not have an official M motor. It's a slap in the face to M enthusiasts but few real M enthusiasts seem to exist these days.
What BMW should do out of the two choices above is what Car and Driver stated regarding using the S55B30 out of the upcoming F80/F82 M3/M4 but what they likely will do is the cheaper route that will not anger M3/M4 buyers. BMW historically protects M models based on their price of entry which means the M5/M6 will always be the top dogs at least as far as power and straightline performance is concerned with the M3/M4 following then the M2, 1M, etc.
Nobody knows what will happen, they are just guessing. If BimmerBoost had its way a lightweight 3100 pound M2 would be produced with an S20 four-cylinder (M engine based on the N20) in order to bring the F22 2-Series weight distribution back to 50/50 and offer the car as a modern homage to the E30 M3. BMW is moving away from its history and traditional M ideals so it would be nice to see them honor their past M models with a modern interpretation as a tribute to enthusiasts and to show they still care. That said, BMW does not care so this will not happen.
For now, everything is speculation. So, feel free to speculate away as well.