Not much this year, highly dependent on the weather patterns, the combination of a warm wet September followed by a hot, dry start to October has resulted in both the ashes and maples simply dropping their leaves.  Rather reminiscent of the UK, actually.  Fall color depends on a set of factors: first the changing daylight, a wonderfully consistent factor, then temperature.  An early freeze means the leaves simply drop, but no frost at all (as in this year) reduces color.  Then there are the individual factors, the type of species (obviously), soil type, location (including zone, exposure, elevation), stresses on the individual tree, and finally the specimen’s genetic make-up (a factor in some but not all species, red maples are highly variable but striped maple isn’t at all).