I sold my DSLR system on Thurs. and purchased a m4/3 system today. The new Pana X lenses created the tipping point for my decision. My main body was a Canon 50D and L and high-end EF-S lenses. I got a Rebel and the light 18-55 and 55-200 for hiking, but soon found it too heavy. I then got an S90, which I love. But I soon found that images from the S90 while fine for posting on the web and for small snapshots, didn't hold up to printing much larger than 8x10, couldn't make a 8x10 if cropped, and were unusable for publication. While compact cameras do amazing things, their sensor is just too small. The S90 and its successors, the LX-5, Oly XZ, etc. are significantly better than most p&s cameras, but the sensor is just too small for serious photographer use. The m4/3 sensor is more than four times larger and it shows, just as a full-frame sensor shows more detail, dynamic range, and exposure latitude than any, even the best, APS-C sensor.
I think you have found your way to what my obsessive mind has identified too as the ultimate hiker's camera: the GF3 with the new X lenses. This is the smallest and lightest kit that will still provide really high quality images. The image quality and focusing speed of the newest generation of m4/3s cameras has come very near to that of the entry and enthusiast DSLR. The other really light competent combo is the new Oly PM1 with the incredibly light 14-42 and 40-150. In fact this Oly combo weighs even less then the comparable Panas at significantly less cost. On the other hand, the X lenses, which haven't been reviewed anywhere yet, claim higher image quality than the standard kit wide and tele zooms to go along with their reduced weight and size.
Rebel 600D + 18-55 + 55-200 = 40 oz.
Oly XY= 10oz
GF3 + 14-42X + 45-175X = 20 oz.
PM1 + 14-42 + 40-150 = 19oz.
So by going m4/3 rather than DSLR, you cut your weight in half.
So by going m4/3 rather than top compact p&S, you gain weight but also gain much longer reach and much higher image quality and much much greater versatility.
So if, like me, you want to make serious images, m4/3 seems to strike the right balance.