I've read though all 15 pages of this thread. Please don't shoot me if you think my response isn't related. I am a Mac IT support technician with 18 years under my belt.
I just set up a new iMac i7 (Late 2013) with 512 GB SSD, 16 GB RAM, 10.9.1. Out of the box I set it up as a fresh Mac - no migration. I fresh-installed the couple of applications that the user required and downloaded all pending Apple software updates. I manually migrated just the things the user needed including the files on her desktop, and various home directories (pictures, movies, music, etc). I didn't touch her home Library folder except for one thing, I brough over her Mail, Mail Downloads folders and com.apple.mail.plist. That's it. I made no changes to the default energy saver settings.
There are no USB drives that are connected to the computer but there is a powered belkin USB hub that has her HP LaserJet printer connected to it.
I configured her computer to back up via Carbon Copy Cloner at 3:00 AM every day over the network to a share point on their server (I do this all the time with many computers across many clients, including my own). I set the CCC schedule to wake/power on the computer when the scheduled time arrives. Last night, she put her iMac to sleep as instructed and when she arrived there this morning, she received the same error you are all talking about -- Sleep/Wake Failure Experienced a Problem
After having read through all that the rest of you have gone through, I'm not entirely convinced that this is related only to MacBooks. I wouldn't be shocked if the new iMacs aren't much different inside anyway.
I have instructed my client to remove the USB hub from her iMac and instead plug her printer directly into the back of her iMac. I won't likely hear back from her until Monday (it's Friday at the time of writing).
I have an original RETINA MacBook Pro running 10.9.1 and I personally have never experienced this issue. I do not plug any devices into my computer at night. I have always had PowerNap enabled. Overnight, my computer performs a clone backup over the network and periodically wakes to do what PowerNap does.
My conclusion from what I'm seeing here is that this is likely a Mavericks problem that may effect only certain (more recent) models or certain setups and that the problem may be related to having non-Apple USB devices connected to the sleeping Mac.
If I discover more, I'll post an update.