Less cluttered, faster, and easier to navigate than Mapquest and Yahoo! Maps; and clearer, too. The maps are easy to read; the roads are well-labelled; it has the whole Google good-enough-to-lick thing.
(Map of home in Mapquest; Yahoo! Maps; Google Maps. Interesting: Google correctly identified which of the 6 Walnut Creeks I was searching for (besides CA, there are towns named Walnut Creek in GA, MS, NC, OH, and SC), presumably because we're the only one containing a Walker Avenue.)
(Update: an analysis on the underlying tech.)