I just noticed that
http://www.nausicaa.net has showtimes listed for 'Spirited Away' this weekend, see:
http://www.nausicaa.net/miyazaki/sen/theaters.php
Looks like the movie is playing in 58 separate areas around the US, so given a few showings in each area I'd guess at least 150-200 theaters are screening 'Spirited Away' this weekend. While they have a disclaimer that 'this is not a complete list of all current and future showings. Cities and theaters will be added as information is brought to our attention', it looks like Disney is re-releasing their pre-existing prints rather than manufacturing & releasing many new prints.
(I'm not convinced that Disney is wrong in not springing for an 800+ run, either. In the US, anime is a direct-to-video product. We are accustomed to buying and watching, not going to a theater and watching.)
Interesting tidbit: a Google search for the word 'away' turns up 'away.com' in position #1 and 'www.spiritedaway.net' in position #2.