Some folks have said their posts aren't expiring. A couple notes:
1. wp-cron (the mechanism WordPress uses for scheduling) only works when people actually visit your site. If you are testing Content Scheduler on a development site, and you're only hanging out in the Administration backend, you may never see expiration happen.
You have to visit a page on your site to trigger wp-cron.
2. Content Scheduler 0.9 only checks your content for expired dates and times every hour. So again, if you are testing, you have to wait at least an hour before you would see changes.
I'm working on 0.9.1 now, to allow folks to set their own amount of time between checks.
3. If you still aren't seeing expirations happen, try disabling the plugin and reenabling it. This resets the wp-cron scheduling.
Version 0.9.1 will report on the setting screen whether or not there is a wp-cron problem going on, so you can take action.