Skype is broken. I tried launching it, but nothing happened after clicking on the icon either in the Dock or Applications folder. I reinstalled it, and now it crashes with an error claiming that the app is corrupt. I tried redownloading the app, same error - but the app works fine on other machines using the same downloaded file for installation.
Parallels is working for me to a certain extent. When I tried to install a Yosemite VM in Parallels, the boot environment provided by Parallels gets to a generic unix bootloader and hangs. Since installing Yosemite also upgraded the recovery partition, I'm currently unable to use it to install a VM in Parallels. Preexisting VMs are all working well, as it my Bootcamp partition.