So does this ruling clear the way for a hypothetical situation such as this?
I hang around a software store and see a customer buy a retail version of KillerAp 1.0.
I buy this software for a very low price after the original owner has had time to install it and of course make a reliable "backup" of the whole package.
Now that I own the "original" can I sell it on eBay?
Sure you can.
The original owner is in violation of copyright though.
Your action is legal under first sale, but the prior owner has an illegal copy. Most large software apps today "activate", or make the current owner beam information about his machine and configuration to he company's server, to be used as validation for his license. If you sell the software, you ave to "deactivate" it before the next owner can activate it.