Hard to tell from where this thread is headed to. (almost like a brand war)
I suggest you look over the Steve Huff review linked in this thread.
However, Steve H. does a real world review, in other words, a "if I picked up the camera and used it AS IS" review, so you must look at it in this context.
If you want a base equivalent starting point on picture files and work up from there in PP then look at other sites (DRP; IR)
From Steve H.'s review, Panny has very conservative metering (there is a strong preference of panny to preserve highlights; nothing new here; Been like this since GF1).
The water/oil tank photo is at least 1/3 stop different (same settings; but ISO160 vs 200).
Steve, does point this out in the replies that it was a 'AS IS' look at how the cameras handle when used 'AS IS' as most users would.
So if you tweak a +1/3 or +1/2 bias to exposure always on the Panny, that makes it the same as the Oly in exp. A simple +1/3 in PP can do it as well.
At the risk of blown highlights (same risk the Oly is running)
Here are the full size ISO 200 and 160 jpegs from imaging resource.
EP3 :
Digital Cameras, Olympus PEN E-P3 Digital Camera Test Image
GX1 :
Digital Cameras, Panasonic Lumix DMC-GX1 Digital Camera Test Image
As you can see color representation is different on both cameras. Which is more pleasing? Which is more correct?
I like the Oly pop in colors, but the mannequin seems a bit to magenta if I compare it to the typical ones I see around Orchard Rd. So Panny colors seem more accurate.
See how well the G3 (another Panny camera) scores against the Oly EPL2 and others in color accuracy :
Color - Panasonic G3 Digital Camera Review
Accurate does not mean pleasing in most cases

GX1 photo is also larger at 16mp vs 12mp, so you need to downscale the GX1 photo or upscale the Oly one to have a more objective comparison on whether the extra resolution is worth it.
So the Panny is not bad when a user wants an 'accurate baseline' to start off with.
Of course, if the user wants, he/she can look at sample review like the ones in IR, and study the color histogram between the oly and panny, to find out roughly what color bias and tone curve needs to be used to get to as close as the Oly colors.
For RAW, its not out yet in DPR, but have a look and play around with the G3 results.
Panasonic DMC G3 Review: 18. Compared to (RAW): Digital Photography Review
High ISO 3200 on IR.
EP3 :
Digital Cameras, Olympus PEN E-P3 Digital Camera Test Image
GX1 :
Digital Cameras, Panasonic Lumix DMC-GX1 Digital Camera Test Image
Other results can be seen here :
Imaging Resource "Comparometer" Digital Camera Image Comparison Page
IMO, if the user does PP on his/her photos (RAW or JPG), the differences in exposure/color/contrast are generally not a big deal.
Since this is a photo forum, I'd think most folks here do PP to some extent (simple or complex).
In fact I use Picasa and just click the "Auto" Tuning and that works fine in most cases.
Just a "S" in the tone curve in PP will yield the necessary contrast and 'pop' in a Panny photo.
Just buy the m4/3 camera one feels worth it and like better.