Simply put: larger sensor, high-quality lens, and user control. Virtually every specification I list basically falls into those three categories, which tells you something about just how miserably the current crop of more than 60 million cameras being sold a year fails. The one thing that isn’t in those categories is a dedicated autofocus system (rather than double-purposing the imaging sensor as almost all current designs do), and this requirement basically points to the other failing of all current compact digital cameras: they aren’t responsive enough.
thom's compact camera challenge
thom hogan has an excellent note on the poverty of current compact camera designs and how it can be remedied. yes, nikon [or canon, or olympus or panasonic]: i would pay $450 for a compact that meets thom's design specifications.