There are a few other threads in the Apple support forum about similar problems, even with the Mac Book Air.
In the hopes of adding more info that will help developers fix this problem, I'm using a 4-month-old retina MBP, and I am running 10.8.3 (so I can attest the .3 update doesn't make this go away).
For me, the scenario often happens when I open the laptop lid after it has been closed overnight. The sounds appear to be associated with notifications of received and outgoing mail from Mac Mail. Obviously, I haven't sent 50+ emails overnight while my computer was sleeping -- much less one -- so I'm not sure where the apparent backlog of notification sounds -- if that's the case -- comes from.
It tends to be associated with longer periods of inactivity -- say more than six hours (overnight) -- rather than just a couple hours during the day.
Like others, my only solution when the sounds just keep going has been to quit Mac Mail and relaunch it. A few times, the sounds have abated on their own; I perhaps don't have enough patience to wait them out now that I know a simple quit-restart will solve the problem.
I can affirm that I am never running Facetime or camera-related apps during these episodes. In an occurrence just a few moments ago, I had the following apps running: Mail, Entourage (2008), Firefox, Calendar, Evernote, TextEdit, QuickTime, Microsoft Excel (08) and Keychain Access.
I hope this helps. Since variations of this problem have been discussed in the Apple support community for at least a year and a half, it's a shame it hasn't been resolved yet.
Jen.