There are a few new systems appearing on the horizon that look like they will allow power control from any iso-compatible hotshoe, including those of mirrorless cameras like mft and Fuji X. But they're typically flash-and-trigger combination specific and are likely to be manual-flash-only on mirrorless. AFAIK, there are no full-function-TTL-capable radio triggers for micro four thirds, Fuji X, or Sony NEX at this time.
This one's actually a bit older. There are reports of this TTL trigger that works with Olympus's RC system to turn the light signals to RF; kind of like RadioPoppers. You should get TTL and HSS with this, and, presumably, remote power control, but reports are few and far between, and you'd still need a mft RC master unit of some kind.
Cactus V6 may not work
Cactus has been talking about the V6 and the RF60 as a way to control the power from any brand to any brand TTL flash. So this could be one possibility, but looking over their current V6 FAQ, micro four-thirds may be out of luck. Their senior marketing specialist, in response to a question about mft compatibility with the V6 wrote:
...currently the V6 does not support TTL flash systems other
than Canon, Nikon and Pentax - that is, for remote power control. So
your Metz unit is running on Olympus / Panasonic TTL system, so the V6
cannot controls its power.
So it looks like the V6 may be a manual-only trigger on mft; although it's unclear whether it's the camera hotshoe TTL or the flash's TTL that's being talked about here (i.e., you may still get power control with, say, a Canon/Nikon/Pentax TTL-compatible flash from mft). However, it's early days yet, as the trigger is brand new, and mirrorless off-camera flash shooters are relatively thinner on the ground, so it'll be a while before a field report comes in on whether or not the V6's learning features or firmware updates will later include mirrorless TTL systems.
The Godox FT-16s triggering system could work, since the transmitter unit works to adjust power in-hand, without talking to a hotshoe, so it's very likely to be mft compatible. But, obviously, it only works to control the Godox flashes.
Yongnuo TX units
And then there's Yongnuo. Right now, it's looking like all three of their Canon triggering systems, with the appropriate flashes, could work for manual power control on non-Canon hotshoes, but except for the YN-560 system, it not make sense to an mft-only shooter.
The Yongnuo clone of the ST-E3-RT, the YN-E3-RT had a firmware update that allows it be used for manual power level adjustment on remote 600EX-RTs (and presumably the upcoming Yongnuo clone of same) from any ISO-compliant hotshoe. However, a 600EX-RT is expensive to use in a non-eTTL system as a manual slave, and having to hit the test button every time before a shot to send the power settings may not be your ideal.
The YN-622C-TX/YN-622C trigger combination can be used with an mft (or other mirrorless) camera to manually adjust the zoom, manual power level, and group on/off of any flash that's compatible with the YN-622C]3 (as in, can be menu-commanded from a Canon camera), such as the 430EXII, or YN-568X. The new TX unit provides the interface that the Canon flash control menu does. Again, this might be overkill if you don't also shoot Canon and can take advantage of the eTTL features of the triggers.
The YN-560-TX can manually control the power level, zoom, and group on/off on the YN-560iii manual flash. But only the Mk III (the one with the built in radio receiver).