Empty Nest?

I'll be the first to admit I know very little about nature.  I noticed this nest last week at the complex where I live and I became very curious. Mostly because as I just mentioned, I don't know alot about nature.  I figured with it being fall, this wasn't the time of year you would expect to see nests.  Then I thought, well, all the leaves are off the trees now, so this could be why I'm just noticing it.  Whatever the case is, I just want to know what is or was in there.  I've tweeted and posted on Facebook and the majority of people say it's a Paper Wasp nest.  Eww...All I know is I'm calling the condo association and having them check it out.  After all, that's what I pay condo fees for, right?