There should be a tweet below, which says "This is a test tweet that I'll delete tomorrow - just trying something out :)". Its URL is http://twitter.com/JoBrodie/status/64760728212611072
(which will soon stop working once I've deleted the tweet).
I'm wondering if Storify pages are dynamically generated, recreating the page by pulling in all of the individual items that make it up (essentially a series of disparate, individual RSS feeds, one for each item). Or they may well be combined and captured into one page with a single URL.
I'm expecting that, if it's the former, then deleting this tweet from Twitter will remove it (after some unknown period of time) from Storify. If it remains here in perpetuity then the second theory seems plausible - mind you there could well be some other reason that I've not thought of.