I am using a G1 and find it excellent choice. I bought it used very cheaply, with the 7-14, 14-45 and 45-200 (steal, because with tripod and CPL all for under 900 USD, everything under guarantee). Recently, I bought GF1 with 20 mm as second body, again clearance sale, cheaper than the lens alone.
And now for your question:
My ideal lens setup would be - for landscape:
7-14 (or oly 9-18), 20 and 45-200
street photography - 20mm (and GF1, weights almost the same but looks smaller)
The 20mm is a simple decision regarding the speed, size and weight.
The difference between 7-14 and 9-18 is, besides the price and 2mm focal length, that the 7-14 cannot take filters, unless you choose diy solution (and probably loose the 2mm on wide end because of vignetting). And then there is difference in size and weight. The 9-18 is better choice rationally, the 7-14 is for the enthusiast (or when you get such deal as I got).
It can be only me, but I tend to shoot quite a lot at the 20mm focal length (40mm equivalent) and then at both extremes. I did recently some hard thinking about ultralight photo setup going along with my ultralight backpacking setup. But this means for me 2.5 kg (ca 5 pounds) in photo equipment at least - with all filters, gorillapod slr zoom and the above mentioned lens setup for landscape / photography. With proper tripod legs (with the gorillapod ballhead) I have an 3.5 kg setup. Limited (minimal) setup for travel in towns will be the G1 and the 20mm lens (better handling for me) or the GF1+20mm (big compact camera / nothing to see here). Neither is truly pocketable, but definitively "transportable".
I can get the 2.5 kg setup all in my (big) handbag with space to spare and have it every day on me, did bike commute to the office with the same setup for more than 5 months. I cannot imagine to do the same with my bosses' 5DmkII and equivalent lenses - nor take the same walks in the summer, every day 5-7 km in my lunch hour as scouting / learning the camera and lenses. And this is the "maximum" setup for every possible need including macro (raynox 250 + diy popup flash diffuser, diy reflectors) and spare batteries.
Back to the lenses: The 14-45 is "better" lens than the 45-200, but I would wish for 12-60 focal range. I use the 14-45 a lot when walking in the town, but I suspect with the arrival of the 20mm recently, my use of this lens will be reduced a lot. As said - there are lot of photos I take at about 20mm and when not, I would often wish for more at both ends.
My suggestion is - examine your photos exactly. When looking at the tele end, how much photos did you take with the 1.4x (or how often did you wish for longer lens)?
For my shooting style, I would go for olympus 9-18, skip the 14-45 range and go for the 20mm instead and the 45-200. For wildlife as specialty, I would either choose different setup at all, or buy an old and faster legacy prime. The manual focusing with G1 and GF1 is very easy(and your GH2 should be the same). You can use the 45-200 for this as well, but it is not an optimal lens, more one "in case" or ideal for zoo or wild parks when you can go nearer, or you need good knowledge and technique for shooting wildlife. It IS an 400mm equivalent but isn't a fast lens. In exchange, you have it in very small and lightweight package.
For more focal length at the tele end, I would get 9-18, 14-45 and 100-300, and the 20 mm pancake. The gap without 14-45 is too big for me. Luxury and lightweight 4 lens setup would be 7-14, 20/F1.7, 45/2.8 and 100-300.
For video, the 14-140 would be probably ideal and if you can live "within" this focal range, good as one lens setup. Another plus of this lens - ideal for travel in group - no fiddling with lenses, treat it as point and shoot. My personal decision (was planned from start) is two bodies setup in such case, mostly because I want to go wider and have backup camera.
Good luck with your decision.
Majka
