Oh no, full frame versus 4/3rds? We've only just swept up the last lot of blood stained wood shavings.
Realistically, 4/3rds is never going to compete with FF in absolute image quality, but it is really a beast of a different nature and not one that is trying to compete with FF. Those who see not just the disadvantage but also the advantages in a smaller sensor will continue to show interest in 4/3rds. After all, 35mm became the most popular general use format with film in spite of the better quality available from medium and large format. It only maintained that position because it delivered the goods to a high enough standard for most purposes. If the same can be said of 4/3rds today, and I personally think it can, it will maintain its appeal to those who appreciate high quality miniaturised photography.
There has always been and will always be those who feel they need the ultimate in IQ available and are prepared to carry around with them whatever it takes to achieve that; and there are those who find they can achieve high (publishable) quality with a smaller format and who love it's portability as they find they have a decent camera with them more often. These are different markets which represent photographers with different strategic approaches to their photography and never the twain shall meet. That doesn't mean that 4/3rds manufacturers shouldn't try to improve performance and I have no doubt that technological advances will bring benefits to sensor performance generally across all formats.
In the end, doesn't there come a point where more and more performance is simply superfluous as it becomes undetectable due to the limitations of the human eye? I'm not saying we're there yet, but I don't think that mile post is a million miles away.