[Artemis]

Compiling some info:

The final version of the M2 base version will not be presented before the M4 GTS (likely we get to see some M2 teasers in the forthcoming weeks/months):

Originally Posted by SCOTT26

After the new BMW X5M and X6M that will be launched later this year [2014]. The M2 will be the next all-new M car. There will be a hiatus until the next M5 but in between there will be the M4 GTS which could use the Orange colour as a nod to Fire Orange.

The M4 GTS will be presented "as preview concept" on August 16, 2015 at Pebble Beach Concours d’Elegance 2015 (California):

Originally Posted by SCOTT26

The first example to take the exclusive road will be the all new BMW M4 GTS which will be shown as a preview concept at Pebble Beach in August.
Essentially the M4 GTS will be a production model of the BMW M4 Safety Car which was the M4 GTS "Concept".

Last Autumn Bimmerpost announced that the product version of the M2 base version will be on display from September 17-27, 2015 at Frankfurt Motor Show 2015 (Germany), and thus not earlier. That info is still consistent with the more recent info. Coincidence: BMW CCA Oktoberfest 2015 (Galloway - New Jersey) takes place during the same period (September 21-27, 2015):

Originally Posted by Jason

Our current information (subject to change) indicates a Frankfurt 2015 (September) auto show debut for the M2 Concept, followed by M2 production beginning in November 2015 for the EU/UK and in March 2016 for the US market.

Originally Posted by SCOTT26

The M2 was there in its final form it was the first time I have seen the car, no Carbon roof , new five spoke wheels and a very aggressive aerodynamic kit which is a more realistic version taken from the GT car which gives the car a very aggressive look. The "fangs" which provide function really add an aggressive look to the car. Its body is more muscular than the standard 2er including the M235i so there is a distance between the two to allow both M2 and M235i to flourish. Wheel arches are broader especially at the rear.
Both M2 and M4 GTS will be launched in late 2015. And both models are considered for further progress.

For 2016, two CSL models (concepts) are scheduled. Let's see whether the M2 CSL is one of these:

Originally Posted by SCOTT26

In 2016 BMW M will provide its first look at concepts of two models which will wear the CSL badge as well as more pronounced bodywork, Efficiency technology and lightweight features to illustrate exciting and lucrative possibilities for progressive performance.

But it remains to be seen whether a possible M2 CSL gets to the US because of legislation:

Originally Posted by SCOTT26

IF we do a lightweight M2 (emphasis on IF). Then I do not see it being offered in the USA because of the cost to get some items from the above past legislation.
For now there will be an M2.

But there may be hope for an M2 CSL getting to the US, as in the meantime the news was revealed that at least the M4 GTS will be on sale in the US:

Originally Posted by MikeBMWVegas

Just stumbled across the 2016 BMW M4 GTS in BMW's ordering system... as of now showing up as week 9 next year.
It does not show what options nor colors nor pricing at this time.