After taking a over a week to read the initial reviews and hype for this new camera these would be the upsides over the E-M5 I see so far for U/W photography. First let me say that I think the E-M5 is an excellent underwater camera and that the Nauticam NA-EM5 housing is one of the best values in the market for a quality camera/housing package.
So what do I see as the up sides for making a switch from a DSLR or other mirrorless to the E-M1. First the electronic viewfinder is the best in the market bar none and has features you just can not get with an OVF. It has a viewing area larger than just about any DSLR on the market except for the $6800.00 Canon EOS-1D, it is even larger than the $6000.00 Nikon D-4 according to reports. It now has excellent AF speed for both M43 and 43 lenses and much improved C-AF speed. Build quality including weather sealing and freeze proofing is even better than in the E-M5. The addition of a wider array of control buttons which are more spread apart and a built in guilty grip will make the camera easier to use both above and below water, i.e. I can better access the controls of the E-M5 inside my NA-EM5 housing than I can above water. Higher speed flash sync of 1/320th and lower ISO-100 both needed to get those black backgrounds in macro we all like and for using wider F/stops above water. At 1/320th with hard wired strobes this camera should give you 1/500th. The sweet new 12-40 F/2.8 Pro lens, I have used the Panasonic 12-35 and prefer it to the 12-50mm zoom this new lens is reported to be the best M43 zoom made and a real winner as my prime travel lens with minimum focus of about 7" across the full zoom range. A 40-150 F/2.8 Pro will be coming in 2014. With my first 43 and M43 cameras I never shot above ISO-400. With the E-M5 I have expanded to ISO-640 and if the reports are correct the E-M1 should allow me to shoot at ISO-800 or more and be happy with the results. With the removal of the low pass filter and the new processing engine image quality improvement over the E-M5 and sharpness have been reported. This is the first high end Olympus release I can remember where the body only option rather than the "kit" option is coming first so that those of us who already have lenses and can live without the 12-40 can have the camera at first release. I like the one touch white balance button on the front of the camera, I used it all the time starting with my E-DSLR cameras. Built in HDR and a host of other features will also interest many.
Who do I see buying this camera, I think we will see an even greater number of converts from the DSLR ranks to this camera which already has an excellent lens set for U/W photography. For those who are still using the LCD (much improved over E-M5) to compose and focus I don't expect to see a large exodus from E-M5. For those like me who religiously use the viewfinder I would expect along with the many other improvements to see some E-M5 owners making the switch. If you are using the 45 or 180 add-on viewfinders this camera should be amazing. Focus peaking has been added for stills and along with the large viewfinder critical focus should be greatly improved. Along with the Olympus housing and based on the great success of the Nauticam E-M5 housing I would expect that Nauticam is taking a very hard look at this camera.
Regarding Guy’s post, most who own the E-M5/Nauticam combo have purchased in the past year and I would not expect that they will all want to jump ship from such a excellent and reasonably priced system. Both cameras will deliver pro quality images, in fact most of the current mid priced camera offerings will do that and to me adding a few more MP’s doesn’t add all that much to the overall quality of the camera. What does is quality lenses and Olympus has an excellent reputation in that area.
Regarding size, yes we would expect to see a larger housing but not that much of a difference V. Nauticam NA-EM5 in fact I would expect to see something larger but still much smaller than the Panasonic GH3 housing size and that will use the same existing ports for current M43 lenses. Yes the housing will cost more but as so well pointed out in the first E-M1 thread by Coroander the camera has a number of new controls. I did not expect to see so many and they should all be accessible in a housing which will raise cost. Again I would not expect to see the housing cost as much as the GH3 housing and certainly not more.
Regarding video, this is Olympus M43 Pro entry camera and aimed at still shooters. As Guy pointed out cost differences compared to Some APS-C and even full-frame cameras should be considered. So consider this, if you believe DPReview the video quality for cameras like the D-7100, 6D, D600, D800 and more all have video quality of about the same level or worse than the E-M5 (do some comparisons in the E-M5 review). Canon 5D, the coming 70D, Panasonic GH3 and the soon to be released Black Magic Pocket Cine M43 cameras will all be better video cameras if that is your interest.
What will not change is that even if you make smaller APS-C and full frame cameras the optical viewfinders will also be smaller and the lenses will remain just as big as they always were. No matter how small you make the camera full frame lenses will still need 230mm domes for best rectilinear results, APS-C lenses will still need 200mm ports and M43 lenses will get excellent results with 170mm ports. As a result the E-M1 system will still be a very compelling travel system for both above and below water photography.