No one thinks that the a7's are going to kill DSLR. However, as I've recently read in a review, the a7's Mk II could. It's impossible not to see the potential, when you consider that they are a world first vs a decades-old, mature, established tech. Possibly surpassed tech? Time will tell.
They have class leading sensors, good tech inside, excellent (though momentarily few and a tad pricey) Zeiss branded AF lenses, and they can take pretty much any lens ever made. And they're small like a MFT camera - something that people like me, who take lots of planes, will be thankful for.
Good thoughts. I just recently found out these cameras existed and my initial thought was, holy crap this could actually replace a DSLR for most of my purposes. Reading reviews it seems they're not all the way there in some areas - AF sensitivity, handling, shutter blackout, battery life, lack of lens selection all seem like little annoyances that would add up. That doesn't mean that the next generation of these cameras won't address those concerns. Sony needs to stick with this platform, listen to users and develop it. Should be a real winner.
One other note on the A7 - I only handled one for a few minutes at B&H, but I have to say my little EOS M feels more rock solid than the A7. I'm sure it's built well but it just doesn't FEEL built well, if that makes sense.