According to USA Today, the m43 (micro four thirds) format is extremely unpopular in the United States. According to the article, "Of the 1.8 million cameras shipped in the Americas (not just the USA) in April, a measly 38,843 of them were mirrorless — 2% of the total."
Also, Olympus received a large investment from Sony last year, so it is easy to speculate on how long they will be in the business of making these cameras. If they decide to drop m43, it would leave Panasonic as the only company making m43 cameras. For those investing in Olympus lenses, this would leave them without image stabilization because Olympus puts stabilization in their bodies rather than their lenses (unlike Panasonic).
I should mention that I am a big fan of the format because of the small lenses and camera sizes. Also, the cameras and lenses are often cheaper than the other formats. The ability to add an adapter and use these cameras with most any lens ever made gives them even more appeal.
However, with so many questions about the longevity of the format, it makes it a tough decision on whether I should invest money in the lenses. Yeah, my EPL5 (my initial impression are here) should work for a long time, but as I mentioned in my other article, there are plenty of improvements that need to made. I currently have 3 lenses and I would like to add a few more, but they aren't exactly cheap.
The popular thought on DSLR lenses is that they are worth the money because they can be used on new camera models in the future and they will usually continue to hold a lot of their value. This allows a consumer to feel justified in spending money on lenses. They are investment for now and in the future. My mindset is that the Canon 100mm, that I bought for a 20D about 8 years ago, will still be in my Canon kit in another 8 years. I worry that the m43 lenses will only work with cameras bought today and in the near future and will not work on cameras down the road. This, in theory, makes the purchase of an m43 lens more of a gamble compared to a DSLR lens, unless you only care about using it today.
My plan is to wait a while before buying any new lenses. I currently have m43 lenses the cover 28-300mm and 20mm f1.7 for low light. When I need something else (which will be rare), I am going to just rent the lens for now. Luckily, there is a lens rental company near by, so I can save on shipping.
I should mention that I may decide that using the camera now with great lenses outweighs the question of future use and buy a couple more lenses . I just can't decide how much money I want to spend on this format right now, which is a major problem for the format if others are asking themselves the same question.
I really do hope the m43 has a future and that the current companies making bodies will continue to improve. I just wonder if the market for these cameras will grow. The smartphone cameras are getting better and better, so the market for the intermediate, small camera could continue to shrink, while a great portion of serious photographers will continue to buy full frame DSLRs because of their many advantages. I guess time will tell and I certainly don't have a crystal ball.