bug in node_example.module: modules will now produce "Cannot use string offset as an array ... error in filter.module line 835"

See benwei's sleuth work here.

http://drupal.org/node/53899

He uncovered a bug for a contrib module (basicevent) but this will become a bug w/ numerous contrib modules, I believe.
The reason is that as of Drupal 4.7 beta 5 or 6, this produces as error:

function mymodule_form(&$node) {
  ...
  return array_merge($form, filter_form($node->format));
} 

So assuming the recent changes to core filter/validation functions are here to stay, you could conclude there is a bug in drupaldocs, node_example.module code. Since many contrib modules use this as a template, I believe many/all such modules will now break.

http://drupaldocs.org/api/head/file/contributions/docs/developer/example...
return array_merge($form, filter_form($node->format));

I gather that anybody who has copied or will copy node_example.module as a start to their new node will have this bug.

To fix my contrib module, I used benwei's lead and changed the above offending line of code to
$form['format'] = filter_form($node->format);

Not sure if this works for all cases. My node module's form validation is still working