As a past user of the Olympus 4/3 cameras (4/3, not micro 4/3), I have been stung by having bought into a dead-end system..... With no warning the system ended.... no more new bodies, no more lenses, nothing said by Olympus.... just silence... This is why I would only consider Canon or Nikon as a system now... and I went with Canon because of the glass...
Don't count your chickens. I was a heavy Canon FD user the day they walked away and stranded me, with not so much as an adapter. Olympus treated you better than that.
The FD mount dates back to before camera electronics and had no way to accommodate autofocus. In 1987 they introduced the Electro-Focus mount (EF) and incorporated into it the electrical signals and power feeds required in the "digital age" of photography. At this point in time they p****d off a lot of users, but unfortunately for them, the world was changing from manual lenses to electronic lenses... the market for manual lenses was dropping like a stone and the electronic lens market was the future.
To continue on, the decision was made to design the new lens system (EF) rather than trying to modify the old system (FD), with a view on long term needs. Since the flange distances were similar, this meant that the only possible adaptors would involve optical elements.... A few very expensive lenses were shipped back to Canon to be modified for the new mount, but for most lenses the cost of modifications would have been worth more than the lens, so most lenses became orphans.
As well, part of the transition from one mount to the other seems to have involved upgrading the optical qualities of the lenses.... For instance, I have an FD mount 800F5.6 lens at work and I am positive that my 70-200 zoom lens plus tele-converter out-resolves it....
The next "revolution" to be expected in Canon-land is mirrorless.... when that happens, flange distances will decrease further and we can expect the EF mount to slowly die out as less and less cameras are made to use the mount. There will probably be a FF version of the EF-M mount that emerges at that time.... and similar to with the EF-M mount, there will probably be an EF to EF-FFmirrorless mount adaptor. I would expect the same thing to happen in Nikon-land as well.... but the ease of making a mechanical adaptor for either system will save all the old lenses this time.