Olympus has been irrelevant in the SLR market for a long long time.

slr is dead.

This is a move that others will all eventually follow. Sony is releasing a starter SLR-style mirrorless body and I'm sure they will follow with higher end A-mount bodies in the years to come. This camera is actually a great deal if it performs well. The only problem being the limited choice of glass to go with the mount. But for those who already own lenses this is an interesting camera.

LOL, 16MP ...... Is this a new camera or a 2008 model ? Revolution ? There is really nothing new or groundbreaking here at all. Micro 4/3 sensor ? That's just a bit bigger than a GoPro, but a gopro does 4k Video, this camera tops out at 1080P 30fps ...... I really don't think any SLR manufacturers are worried at all ....

When Olympus initially announced the release of an OM-D I was, along with many others I'm sure, incredibly excited. The prospect of a digital body based on my beloved OM-1 which I could use my zuiko f1.4 lenses on was almost too much to bear, sadly that camera or indeed this does not deserve to have OM anywhere near it. 4/3rds sensor? Digital viewfinder? Come on Olympus! Give us a proper compact slr camera with a full frame sensor an optical viewfinder and a simple light meter and you will send millions! Am I alone here?

Forget the Sony NEX, that was last year. Look at the Sony NX

All the specs don't compare image quality. It would be tough to beat the 6D for a similar price point. Will be hanging out for DPREVIEW to comment on this newby - maybe.

Matthew: Actually, quite alot of OM glass performs wonderfully on micro4/3. Not the 50f1,4 though. Too soft. But the 50f1,8 is great, so is the 135's, and of course the superb 90f2 macro, and many more. They all get the best stabiliser in the business, and the evf can magnify up to 14x while stabilising. Don't bash it if you don't know it.
S26t: when ridiculing 16mp of resolution; do you find the mighty nikon d4 a "lol" camera? I have printed 50*70cm with a 6mp d70, looks great. It's all about the glass. And that is where micro4/3 is superior, performance vs price and size. As for revolution: 10 fps for 50 raw-files? That is pro performance at a bargain.

These haters are gonna hate, but they clearly havent put their hands on the EM5 or EM1. I shoot weddings professionally. I have done so for the last 4 years and pull between $2k-5k per wedding. So I'm what you would call a "real professional." I bought the OMD EM5 a year ago and have begun to build a strong portfolio of primes. About 6 months ago I decided to do a test with my 5Dii and all of my L lenses against my OMD and its primes.
The results were so amazing that I have now ditched Canon. My images were consistently sharper across the board with the OMD (by a significant margin). The L lenses are a joke in comparison with the Zuikos primes, especially for the huge price tag and the ridiculously heavy weight of the lenses. The difference in high ISO noise was hardly noticeable. Yes, I do get slightly less DOF, but I still get amazing DOF with my 45mm 1.8 and my 75mm 1.8.
I just purchased the EM1 and now I know for sure I made the right decision to dump Canon.
The Olympus system has allowed me to offer something to my clients that I could never do with a Canon. Fusion films. I am one of 2 people in my entire market that offer Fusion Films to my wedding clients. And I can do this with ease.
Perhaps the most revolutionary part of the OMD's is the 5axis stabilization. It is scary good. Like "how does this even exist" good. I am able to hand hold video and make amazing dynamic movements that make it look like I'm using a crane or steady cam. UNBELIEVABLE!
There is nothing Canon could do at this point to make me regret my decision. Anyone who hates on this system has never tried it and is speaking out of total ignorance. Haters are gonna hate...

Jordan Taylor Bunch, totally agree with you. I have the EM 5 and have been surprised at the quality. I have been photographing for almost 14 years professionally and I would compare this camera quality to possibly a Nikon D300 and the noise handling about a Canon 5d Mk 1. However, i was shooting commercially with those cameras for years and they were great and perfect. I love the compactness and the price tag.
One thing i found out about this camera that i love is the use of ND filters with flash. Since it has an electronic viewfinder the camera actually can compensate for the ND filter so it doesn't look like your focusing in pitch black. I do wish that we can see a greater sync speed for these cameras since theres no actual shutter.
Anyways great camera, its only going to get better from now on. Just because the sensor is smaller doesn't mean technology won't catch up. a 250 mb hard drives were the size of a car half a century ago, now a 64 gb hard drive is the size of thumbnail.