I must admit that this question has been uppermost in my thoughts about Curiosity now that she is down safe and sound and checked out.
NASA gave us the answer yesterday: she will check out an area called Glenelg where water was thought to have flowed and been deposited. After that, it will be on to Mount Sharp.
Check out the details here: http://science.nasa.gov/science-news/science-at-nasa/2012/17aug_curiosity2/ and http://www.nasa.gov/home/hqnews/2012/aug/HQ_12-287_Curiosity_First_Drive_Site_Chosen.html
Wheels should be moving very soon - hopefully next week!
Sky Guy in VA