I'm a gear collector more than I like, and I tend to buy the next camera before parting with my previous, if at all.
I agree with what LostArk said; liquidate the 24-105 if you need to fund the 4/3 system, it'll almost pay for the OM D5. If you don't like the 4/3 after all, you may have a bit of a loss selling the thing but you can buy back another 24-105 for about you'd have sold yours for.
I agree with PixelReaper too, the OMD5 is getting really good reviews on its IQ and may be exceeding the performance of the 5D2 at lower ISO by a noticeable amount. (not all that hard to do, IMO)
I've read that it's raw IQ is comparable to, and may be even a little better for low ISO noise, than Nikon's D7000 which is pretty impressive and far ahead of Canon's anything.
I love the way the OMD5 fits in my hand w the optional grip and extra battery attached. I'd like to shoot with it, it just feels inspiring to me.
I'll wait until DxOmark's test results for it are published as I didn't get to record any files from the pre-production demo unit I played with back in spring. That could be in September or October. And that'll be after Photokina so I should have good info to work with regarding whether I'll step into the 4/3 system as well. I could fund one by selling off some low end Canon gear I rarely use.
I think the OMD5 is the first 4/3 body to really fulfill most customers' expectations of what that system should be able to achieve. Any Oly' may bring out something even better soon so worth keeping an eye on them.
If some good T&S wide glass comes along for 4/3 then I'm sure you'll enjoy using it more than the beastly EOS gear. You're not likely to miss the marginal difference in DoF for the majority of your shooting either.