incrediBILL - 9:03 pm on Aug 8, 2010 (gmt 0)
if you keep it hidden Google will not have record of any links to the page when they find it
When Google crawls a single page from a sitemap it doesn't know of any other links to that page already, this is nothing new.
My suggestion is just a possible a way to establish content ownership by flagging it to be crawled before being displayed to the rest of the world, thus bypassing aggragators that may be indexed faster than you from claiming the content first.
Once Google crawls that new page, you can use another sitemap ping to show them a page that links to that new page.
It sure would be nice if they honored such a simple scheme to prove ownership.