I have several Four-Thirds lenses--2 Super High Grade lenses (14-35mm, 35-100mm), 3 High Grade lenses (14-54mm, 50-200mm, 50mm macro), and 1 Leica/Panasonic lens (25mm). Weaning myself from these lenses will be difficult because they're quite amazing. I've found myself time and again disappointed by the majority of micro Four-Thirds lenses. Those few that are great, are getting some reinforcements.
As they cast off their Four-Thirds line of dSLRs, they brought forth lens designs, in-between the HG and SHG lines of Olympus Four-Thirds lenses, but this time for micro Four-Thirds, and with constant maximum apertures.
The 12-40mm f/2.8 is already available and it's very good, positioned between the 14-54mm f/2.8-3.5 and the 14-35mm f/2.0 Four-Thirds lenses.
The 40-150mm f/2.8 seems to be on-schedule and should arrive about halfway through 2014. I suspect that the image quality will be roughly the same as the 50-200mm f/2.8-3.5 and not that close to the 35-100mm f/2.0.
Prior to CP+ expo, they showed new mockups of a 7-14mm f/2.8 and 300mm f/4.0.
The 7-14mm f/2.8 obviously has a larger maximum aperture than the current 7-14mm f/4.0 that is highly regarded by Four-Thirds users. As with any ultra-wide lens, it has a convex lens element in front, meaning that adding an optical filter is not easily possible and the lens doesn't support them directly. I've been considering the Four-Thirds lens quite a long time, as the weather-sealing is a major factor for me. I see a demonstrator available every so often for a considerable discount. However, f/4.0 is difficult to use with the older sensors, unless I carry my cheapo studio lights with me, and somehow power them in an occasional outdoor twilight shoot.
The 300mm f/4.0 has a smaller aperture than its Four-Thirds equivalent, a rather huge lens that is/was priced at US$5999.99, I believe. That could be the price of the 90-250mm f/2.8. They were within US$1000 of each other. The 300mm f/2.8, like the 90-250mm f/2.8 was built to order, rather than trying to stock something so complex and unique. The f/4.0 lens will be much less unique and won't be able to be that heavy but hopefully, won't rely on electronic tricks to fix optical flaws, due to its smaller size. I would expect that the 300mm f/4.0 will be roughly twice the price of the other three, possibly US$1999.99. If higher, I don't see it going for more than US$2999.99. Photographers of birds would surely like lighter equipment, but I wonder if the maximum aperture will cause them concern. If WiFi was enabled, they could have several of them pointed at a certain sport from different angles with the savings they got from not buying a 135 format 600mm lens.
It's good to see Olympus finally decisive again, after 10 years of an almost completely aimless walkabout, even if there were some interesting highlights.
Update 2014.02.20: I bought the 12-40mm f/2.8 lens yesterday. It's good to have a somewhat wider view, from 14mm to 12mm. It made quite a difference--between getting the shot and getting part of the shot. The lens feels right at home with the GH3, despite the lack of image stabilization. It's sad that it won't work on the E-5 but times change.
Update 2014.02.25: After a few days of use of the 12-40mm, I'm as much in love with it as the 14-35mm f/2.0 lens, but with slightly lower expectations. The great thing is that the lens hood is small enough to carry with me, though I can't imagine it's big enough to be incredibly effective. I'm trying to remember whether I used it during the Olympus photo walk when the sun was just over the state capitol building and the Panasonic lens gave me huge lens flare but the Olympus lens mostly rejected it, even with the sun in the frame.
Could these keep me from moving to FujiFilm?
Update 2014.03.19: The 12-40mm seems quite amazing for the price. It has brought new life to the GH3, as the color is so much better than that of the 35-100mm f/2.8. Sadly, I have to wait for the 40-150mm f/2.8 lens to come from Olympus, but that should be around September, which will likely be a good time to purchase the Panasonic GH4. Since the GH3 has a larger grip than the E-M1, I doubt I'll have any trouble keeping my hands steady during sports. If I can do it with an E-1 that doesn't have stabilization, and the 50-200mm f/2.8-3.5 or E-5 with the 35-100mm f/2.0, I should be able to handle the GH3/GH4 and 40-150mm f/2.8.
Update 2014.12.16: I'm interested in the 40-150mm f/2.8 lens and it's available now, along with the 1.4x teleconverter, though I noticed something disturbing earlier.
I found this comment from Jordan Steele concerning his review of the Olympus 40-150mm f/2.8 lens and also concerning the Panasonic 35-100mm f/2.8:
The Panny is way better in the flare department
Now, I'm concerned about the 40-150mm f/2.8 lens, considering my previous experience with my 35-100mm f/2.8 lens and huge lens flare.