I'm just back from Victoria and it seems a good time to discuss what is a good travel camera. What I took was my 40D, 18-55IS and 55-200 IS. I made good use of the full range, occasionally wishing I had wider than 18 - but probably not enough to want to carry an extra lens (and remember you can always stitch - even hand held if you are reasonably careful).
I have just read dpreview.com's review of the Panasonic GF1 which got me to thinking about camera size. No question that the GF1 is significantly smaller than the 40D, but what about the size of a 28-400 mm.(full frame equivalent) kit look like. Yes, that 20 looks small and cute - but no IS and frankly a lens that is smaller than my 18-55IS would not be all that helpful. The Panasonic 45-200 doesn't look all that much smaller than the 55-250 I have and would need an adaptor anyway. Net result is a very small camera would not make for an especially small kit. My case could be one size down but frankly that doesn't really make a difference.
What really happens with camera kits is that things change when there is a quantum jump in storage - from a carry bag to a belt clip on to a rain coat pocket to a shirt pocket.
My wife's Panasonic TZ5 (now replaced by the ZS-3) is shirt pocketable and covers better than the same range. Of course I lose a view finder, manual controls, high ISO, rapid focusing, and the ability to make larger than 11X17 prints. The GF1 will still require an over the shoulder case and two lenses and won't make a fundamental difference to carrying, storing and accessing the camera - so is it worth both the money and the compromises to have such a system? I suspect the answer for me is no. I guess it might be a nice carry around camera when you don't want to have more than one lens and are willing to live with the size of a zoom or the lack of zoom and IS in the 20 mm. lens. For some, that is all they need, it just wouldn't work for me - I'd miss the longer focal lengths.
What have you been thinking about these new small camera, decent size sensor models?