The Iconmaster has posted a great way to view iOS screenshots in Photo Stream using Finder. To view photos instead, simply change the search string from ‘png’ to ‘jpg’.
Quicksilver can browse Finder’s saved searches in much the same way as a standard folder. Find the saved search in ~/Library/Saved Searches/ and drag the search folder icon to the list in Preferences>Catalog>Custom.

Call up the saved search in pane 1 and right-arrow in to see the photos. The latest ones should appear at the top of the list.

In a scientific test on one image, it took 7 minutes for the taken photo to appear in Finder.