Google told us at Search Engine Land specifically that the tool is smarter by analyzing the content of the URL you submitted and letting you know what options you have based on the details of the cache result, search results and the actual live page.
You can remove complete pages if the page is actually not live or blocked to spiders. You can remove content from a page if the content shows in the Google cache and is not live on the page.
Here are some screen shots:
Now, it may even work on soft-404s, so be careful. As WebmasterWorld's moderator said:
This makes technical SEO aspect even more important, so that your site is not exposed to URL removal requests from the third party.
Forum discussion at WebmasterWorld.