Adding little numbers to custom post types admin menu entry

[bmb]

It would be useful to be able to add the little numbers (like comments awaiting review or plugins needing update) next to my custom postws menu entry.
One idea of how this may be done: Have a filter like admin_menu_label_{$post_type} where the HTML for the circle can be added.

[nacin]

This isn't necessary in 3.1. The menu_name label can be used.

[ocean90]

See r18472.