Fatal errors in get_body_class() in latest trunk (15268)

[uglyrobot]

View any page in a theme that uses get_body_class() (2010 for example) and you get a fatal error:
Catchable fatal error: Object of class stdClass could not be converted to string in wp-includes\post-template.php on line 432

Seems the $page_id var is getting overwritten by the $wp_query class when passed through $post = get_page($page_id);

Confirmed in WP and multisite with no plugins.

[nacin]

Broken in [15265]...

[ryan]

(In [15269]) Avoid var name collision. see #13929

[jorbin]

I can confirm that Ryan's fix works for me on php 5.2.9 with 2010