A report from Auto Motor und Sport in Germany says the SLC is too expensive, and won't likely see production as a result. Whether that means it's too expensive for Mercedes to develop or the end product would be too expensive for its place in the market (up against the $80,000-$200,000 Porsche 911's many variants) isn't clear.
It's also not clear where Auto Motor und Sport is getting its information--the article cites only "company sources." For now, consider it a rumor regarding a car that hasn't actually been confirmed in the first place--in other words, anything is possible.
2015 Mercedes-Benz SLC AMG spy shots
We may have to wait until much closer to the predicted late 2014 arrival date of the SLC to learn anything official on its production--or its early demise.