This is in a friend's garden (zone 5) and she can't find the tag for it. I thought it might be an aruncus, but probably not.
Looks like Sorbaria sorbifolia. See.... http://www.urbanext.uiuc.edu/shrubselector/detail_plant.cfm?PlantID=441
Small stature and pale markings on leaves suggest it may be the new colored foliage cultivar 'Sem'. http://images.google.com/images?gbv=1&hl=en&c2coff=1&ie=ISO-8859-1&q=sorbaria+sem
Thanks everyone. You certainly seem to have it. I don't know if the plant had bronze foliage in the spring (if it's 'Sem'), but I'll find out. Sem appears more compact, and since we tend to share plants.............