On the Epsilon platform cars, it seems to be a strut thing...and very much so, some do, some don't, though those that do are most often reported when it's cold. The Aura guys have discussed it in much detail, to varied degrees of results.
Our '08 refuses to make any noise (struts or elsewhere) after 12k miles and a year, but sometimes--not always--when it is really cold I hear the light clunking from the front end of my '09 over bumps. Not really even noticeable to bother with, as cold does a lot of things to a car, but still. The '07 Malibu rental I had for a month had a nasty clunk-clunk-clunk over bumps from the driver's side that was, again, the strut pretty clearly.
Here's some pretty recent Aura threads, including the first where one just had parts replaced...but still has an issue:
http://www.saturnfans.com/forums/showthread.php?t=132707
http://www.saturnfans.com/forums/showthread.php?t=132835
http://www.saturnfans.com/forums/showthread.php?t=122605
And others...just search their forum for clunk/strut/rattle, etc. They have some more time under their belt with the Aura than we do, so often they have a little more detail on common issues.