I can confirm this is a problem, but I get different errors. Using Chrome on OS X:
load-scripts.php:391Uncaught TypeError: Object function (a,b){return new e.fn.init(a,b,h)} has no method 'widget'
load-scripts.php:62Uncaught TypeError: Object [object Object] has no method 'sortable'
5/wp-admin/post.php?post=956&action=edit:551Uncaught TypeError: Cannot call method 'switchto' of undefined
And using the latest Firefox for OS X:
c.widget is not a function
[Break On This Error] (function(c){var a=0,b=9999;c.widget("...lement:this.element},d)}})})(jQuery);
load-s...320fc76 (line 391)
a(".meta-box-sortables").sortable is not a function
[Break On This Error] var postboxes,is_iPad=navigator.userAg...pbshow:false,pbhide:false}}(jQuery));
load-s...320fc76 (line 62)
And this completely breaks JavaScript for the post editor. I have nothing but Akismet turned on and Twenty Eleven is the theme.