So, I know you have all been on pins and needles waiting to learn the outcome of this little mystery...ha! I heard back from the previous home owners and they did indeed leave the speakers behind on purpose...hard to believe! I feel better knowing this.
I have not had a chance to plug them in yet but plan to do so...I may still try and sell. I will definitely advertise them on this site first though. Let me know if anyone is interested.
Thanks again for your helpful replies!