^^^I agree...my bag with a GX1, 45/1.8, 12/2, 25/1.4, 17/2.8 and 40-150 weighs next to nothing and offers a huge range at high quality. I will often carry the exceptional 7-14 instead of the 12, or my Rokkor 135/2.8 instead of the zoom....but gives great flexibility in a kit 1/4 the weight of what I was carrying with my DSLR bag, and that's including the bag.
I also love that I can put my GX1, 12/2 and 45/1.8 in a tiny hip pouch and basically carry nothing, but have a very capable little walk around kit.
The E-M5 looks realty sweet, but I will need to sit out the early adotin phase on this one and wait until prices drop, since I just got a GX1, and my GH2 is also great and offers almost all of the real things the E-M5 does with the exception of weathersealing , that awesome IBIS and the sweet looking aesthetics. If I can...maybe next Christmas I'll sell my gH2 and get a bunch of gift cards for Christmas to get this. :-)