Since the upgrade to Yosemite I experience random (though frequent) sleep wake failures. Unlike many others I did not have the problem with Mavericks. I opened another posting as my problem manifests itself slightly different to what others have posted.
Basically after sending the Macbook to sleep and closing the lid, after some time (not touching it) I can see the Apple logo lighting up and I hear the boot sound. The Macbook crashed during sleep mode, wakes up on its own and reboots. And then stays ON though the lid is closed, draining the battery until its flat.
My hibernate mode is set to 0 as I have an SSD and 16GB RAM (writing 16GB of RAM constantly to the SSD drive isn't really a good thing to do).
Hardware
Model Name: MacBook Pro
Model Identifier: MacBookPro10,1
Processor Name: Intel Core i7
Processor Speed: 2.3 GHz
Number of Processors: 1
Total Number of Cores: 4
L2 Cache (per Core): 256 KB
L3 Cache: 6 MB
Memory: 16 GB
Boot ROM Version: MBP101.00EE.B05
SMC Version (system): 2.3f36
Error Report
Date/Time: 2015-01-24 09:22:57 +0100
OS Version: 10.10.1 (Build 14B25)
Architecture: x86_64
Report Version: 21
Event: Sleep Wake Failure
Steps: 9
Hardware model: MacBookPro10,1
Active cpus: 8
Process: airportd [38]
Path: /usr/libexec/airportd
Architecture: x86_64
Task size: 2536 pages
MacBook Pro with Retina display, OS X Yosemite (10.10.1), null
