[wp-hackers] Post name permalinks and default post types

[Funkatron]

So, I was combing the internet on how to implement the elusive%postname%
permalink for a custom post type.  I know that it can be done without a
performance hit now but I  was running into issues on how to implement it.
 Everything I tried either didn't work or worked but screwed up permalinks
for pages.  I think I have a solution but I wanted to run it by a few
people to make sure I don't inadvertantly cause any issues:

Basically, I've found that the reason post name permalinks are so tricky is
that WordPress doesn't know what post type to use.  Any rewrite I did would
override page's rewrite or cause WP_Query to default to post.  So, after
much problems and testing, I did 3 things:

1. I set the post type in question to have rewrite set to false

2. Used add_permastruct to create the post name permastructure so WP can
create the permalink

3. (the part I'm worried about) used the parse_query to resolve the
conflict issue:
$post_name = $query->get( 'name' );
$post_type = $query->get( 'post_type' );
if( ! empty( $post_name ) && empty( $post_type ) ) {
$query->set( 'post_type', array( 'post', 'page', 'custom_post_type' ) );
}

So basically, if name is set and post type isn't set, set the post type to
post, page and the custom post type.

My question is can anyone with greater knowledge than I to the inner
workings of WP, think of any unforeseen side effects to doing it this way?
 So far it seems fine to me; doesn't screw up pages or my custom post type.
 Only thing tht might be a problem if there is a post of another post type
with the same name, but I'm not sure how WP handles duplicate post names of
different post types.

Thank you for any comments!