Are d-slrs dying? That question doesn't really frame the camera/photography segment very well. What *is* happening is that the explosive growth era for d-slr sales has ended after about 13 consecutive years of straight-up growth. The early d-slr era had very few models to chose from, with a single Canon the D30 for a long time, against the Nikon D1 then D1h and the Fuji S1 Pro, leading to slowly, more models, and then once the Digital Rebel and the Nikon D70 premiered below $1,000 the sales exploded. But those days are long gone. We're now where we were late in the 35mm film era; that is to say, we now have fewer manufacturers, and fewer choices that are "clones" or "near-identicals".
The "other" camera makers that used to be in the d-salr market, like Fuji and Samsung (using Nikon and Pentax body platforms at one time) have dropped the idea of competing against Canon and Nikon directly, and have branched into all-new areas. Kodak is bankrupt and has left the d-slr market. Sigma's d-slr offerings,going back 12 years or so, have fallen flat on their face. Contax, an early d-slr full-frame maker, is out of the camera business.
Now we're seeing the non-Canon, non-Nikon manufacturers trying to differentiate their offerings from those of the competition, struggling to find anything that can set them apart. Pentax has gone to a medium format 645, and still makes some d-slrs. Sony's hedging its bets on multiple camera types. Samsung is going high-MP APS-C. Fuji quit building on Nikon d-slr bodies and went to APS-C mirrorless offerings.
I just got the big
B&H Photo catalog a week ago. There are plenty of d-slrs (aps-c,FX,MF) for anybody who needs one, in price ranges from $399 to $50,000. Plus hybrid MILC models that function very much like a d-slr and have most of the advantages of a d-slr. There are PLENTY of d-slr models and price points, but there are also a lot of other types of cameras available too.