I have seen these 2 at about the same price, and I am stuck in my decision process.
the Sony seems to have better image quality and quicker flash recharge times. Per Steve's review, the Canon shows some noise even at 200 iso, but also says below 400 iso are above average...I have/had an a510(the lcd screen died), and the image quality looked good to me, so I might not even notice a difference.
I was attracted to the Canon because it can use AA batteries, but everyone recommends getting rechargeables to shorten flash recharge. (which negates having to buy sony only memory for me)
I'm thinking better image, less lag between pics, the sony seems to be the better camera here.