Hi there, I recently got myself the 14-140mm and I think its a great all in one solution for me.
I'm keeping the 14-45 as its much lighter and more compact compared to the 14-140 and because I'll have my original g1 kit not broken up -I think will sell better complete in future.
When i bought my 14-140mm I did think about buying the 45-200 lens instead, to partner my 14-45, but 140mm is more than enough for me at the moment. So i bought the 14-140mm as its a very flexible lens, and thought if i ever need more than 140mm, I'll buy the planned Panasonic 100-300mm in future.
Here's 2 images, one at 14, the other at 140mm I took today, both Jpegs straight from the G1-
(don't mind the composition and exposure etc, I only got the lens yesterday and was getting a feel for how much zoom the 140mm was.) Have to say at 140mm hand held the image was suprisingly unblurred!
Hope the images help you decide about the focal length, in my opinion the 140mm is plenty and I dont need the extra 60mm the 45-200mm would give - so I bought the 14-140mm as it would stop me from changing lens all the time - as I'm lazy ;-) and it would mean less lenses in my collection.
I have to say my plan is to get the 20mm 1.7 as my second lens, with a GF-1 as it would be more discreet, so my plan is pretty much what you had in mind but with a GF-1 - I think that the 20mm + 14-140mm complement each other really well