Overture has had a similar tracking tool for 6+ months (which works great, btw)
1) If you're referring to the Marketing Console, it's also not free. 2) I've had ridiculous amounts of headaches from their system's flakiness. For WEEKS it didn't correctly process Google cost data, and when I asked for a small reimbursement of Marketing Console fees, I was told bluntly that Google cost data wasn't one of the guaranteed parts of their service. I didn't know whether to laugh or cry at such a ridiculous statement. 3) Their stats system can't be accessed from FireFox. Or pretty much any Mac browser.
What a joke. I'm sorry I ever got clients hooked on Overture's Marketing Console. Unfortunately, I don't think AdWords' new cross-channel stats will be a replacement, since they don't even claim to measure Overture costs (so much for ROI tracking, in other words).