I have an alternate perspective.
Mirror less cameras are not the demise of entry level DSLRs, they are the evolution of Point-and-shoot cameras.
Point-and-shoots needed to advance to offer a point of difference from the camera people already have built into their current smart phone. To convince people they NEED to buy another camera, they had to introduce DSLR-like features into their market. Let's get serious, "mirrorless" cameras aren't a new category- they are just point-and-shoots with interchangeable lenses. And the majority of consumers who buy them and entry level DSLRs never even take the kit lens off!
The only chance for mirror less cameras to erode the DSLR market is for pros to start using them. People buy affordable DSLRs to feel like they have a "pro quality" camera. Most will never bother to learn what an aperture is, nor have any idea how big their sensor is. They basically have expensive point-and-shoots.
I live in Brooklyn, NY. Over the weekend I was at Brooklyn Bridge park with my family- the place was flooded with tourists from around the world. People had cameras around their neck every place I looked. 9 out of 10 of those cameras were Canon xxxD/ xxxxD. The other 1 was split between the occasional Nikon DSLR and Sony NEX.
My conclusion is Canon is doing fine. Nikon is the company that NEEDS to be aggressive to stay relevant.
How many TV shows and fancy directors are shooting award winning films on NIKON DSLRs? Canon doesn't need to advertise. Their free PR is huge! When consumers can afford to buy the equipment that they perceive is capable of shooting an episode of HOUSE, well, it helps.
Another thought:
Why can't people consider the fact that The 5D3 isn't over-priced, but that Nikon is taking a huge hit financially in reducing their price in hopes of taking some of the market back? Competition is great! Canon will continue to push back. They now don't have a choice.