Is M4/3 being left behind ? Features-wise

That's exactly what it is. Every year it's a leapfrog by the other companies that were left behind. I don't think any company is at the point of releasing a flagship product (with the latest and greatest tech) every year. It takes 2-3 years for a quality product to "cook" so to speak.

Olympus, this year, is taking care of their 4/3 line--and I'm sure will have something really great in store.

And, about PDAF: It does worry me a bit that the other companies are not going with CDAF because maybe they see limitations in the technology that cannot be overcome. But it's possible that CDAF is better for the 4/3 sensor than what the other companies are utilizing. I'd rather be patient and see how far Oly and Panasonic take CDAF before pushing any warning buttons.