As you may know, Pear OS is an Ubuntu derivate, using a customized Gnome Shell DE, called Pear Shell.
Pear OS 8 will be based on Ubuntu 13.04 Raring Ringtail, and will have a design inspired by iOS 7, which has been recently released. The following screenshot was dropped on Google+, in order to show the resemblance between iOS 7 and Pear OS 8.
For now, the latest version available is Pear OS Beta 2, which has been released at the beginning of September 2013. More information about Pear OS Beta 2 can be found here.
Download links for Pear OS 8 Beta 2:
Pear OS 8 Beta 2 for 32 bit systems
Pear OS 8 Beta 2 for 64 bit systems
When Pear OS 8 stable will be released, you will be able to upgrade from Pear OS 8 Beta 2 to the latest version available, from the terminal, just by doing the following:
$ sudo apt-get install update-manager-core
$ sudo do-release-upgrade