sorry to sound like a broken record... people are going to start hating me because all I seem to do is mention the Canon S5 IS since i've started posting again... LOL!
I believe the S5 meets all your requirements except the 1st one, the sensor size... But I believe I could put a check by all the other items... except maybel also the IS system... Not sure if the S5 IS is an optical system...
I have been doing photography for over 20 years... I bought my first digital camera around 10 years ago, when cameras were LESS than a Megapixel! I've owned a number of cameras since then including my Canon 20D... I bought the S5 as a "Family" camera to use around the house for the quick point and shoot moments... And I most say I grab a lot more shots with the S5 than I imagine I ever thought I would! Pictures have been great! And more importantly I'm grabbing shots I might not have bothered with if I had to lug the 20D around! LOL
oops... just seen Photo 5's post... the S5 also has a hot shoe which is nice since my old canon 420EX flash works with the S5.