This thread has been great. Thanks to all who have posted. The trackpad on my MBP Retina 15" (purchased Jan 05, 2013) started doing the same thing LAST NIGHT (Aug 31, 2013). Out of the blue, and without me touching the computer, my pointer started moving about erratically and selecting objects left and right and wreaking all kinds of havoc on my desktop. I could only get slight control of it by using a USB mouse. So, I went into Settings->Accessibility and selected "Ignore built-in trackpad when mouse or wireless trackpad is present". This enabled me to use a USB mouse and regain control of the pointer, which is vital for me as this laptop is my work computer as well and I cannot perform my engineering job without it!!!
I did try cleaning the track pad (which I do every night anyways) and using a toothpick to clean around the edges (which were already spotless). No good. Tried all the diagnostics (disk verify, permissions verify) and reinstalling OS X 10.8.3. All no good. Problem persisted.
So, I have an appointment with the Genius Bar on Tues and am hoping they can fix it with a new trackpad and battery as per Dugan's experience above. However, this eposode - as well as an earlier one in which I lost the ability to log into the computer, solved by reinstalling the OS - has eroded my confidemce in this product for my job. Given these two problems, I almost a need a backup Mac of some kind in case this happens again! The whole reason I went through the pain of converting to Mac from PC earlier this year was so that I'd have some reliability for my job.
I have also taken to backing up every night to two backup drives in case of failure. Given that I'm into this rig for a good $4K with the laptop and all the additional hardware and software, I am not too pleased at this point. 😟