No Market Share movement for WordPress 2.5 yet sorry.
Get a list of 17,777 websites using WordPress 2.5 which includes location information, hosting data, contact details, 4,159 currently live websites
and an additional 684 domains that redirect to sites in this list. 13,618 sites that used this technology previously and 966 websites in the United States currently using WordPress 2.5.
Distribution of locations of all WordPress 2.5 customers we've ever tracked.