OK, I have a feeling that I know the answer to this one, but here goes.
Currently doing all of my "light" traveling (meaning that the D700 or LF is left behind) with my GH1. Almost always travel with the 14-140 + 20 + 7-14 set. A couple of weeks ago I had a little time to escape on a business trip to Italy and actually was fine with just the GH1 + 14-45 + 20 + 7-14.
I'm really very pleased with the performance of this gear and it's great to be able to always bring a good camera even when I have to travel extremely light.
I should add, by the way, that this is a stellar travel combo with an iPad -- shoot RAW+ JPG, transfer all to iPad, keep cards as "backup" and am usually confident enough to use the iPad to cull on the road -- import directly to LR when I return. Just works great.
So here's the deal. I have a G1 and it is not seeing any action as traveling with both G1/GH1 is just bulky enough that I don't do it. So G1 is probably going to be sold off.
What I *really* want is something noticeably smaller than my GH1 that will give me better IQ than my pocket travel cam (a TZ5 that is my "beater" and looks it), and has strong low light performance. Something that I can throw in my bag if I don't want to take the GH1. I guess short tele is fine or a fast prime for a lens.
Hence my dilemma. My practical side (not to mention my better half who will not find this amusing) says to sell the G1 with it's original kit lens and replace it with the GF1 + 14-45 + EVF (current good deal at B&H for $700 total)-- marry it to my 20mm and be done with it. Cost ~ 400 net I guess.
My gearhead side with endless GAS says to sell the G1 body (keeping the 14-45 because I do like it). And buy an NEX-5 + 18-55 , and an adapter for my PenF 38 1.8. Advantage of this, besides the general joy of new gear is that the low light performance is clearly excellent and it is definitely very small. If the 16mm pancake was a little better/more practical ( I really prefer the 40-50 focal length for a fast prime) I would go with that package instead, but I think it is too limiting for a single lens. I won't calculate the cost to avoid sadness.
Opinions? And yes, I suspect the first option is a no-brainer, but figured maybe someone could convince me otherwise...