Hmm... Has anyone else had any luck in using Outlook with the new preview version? I ended up un-installing the Preview, repairing my existing installation of Office 2013 Pro to get Outlook back up and running. I then tried installing the Preview again although this time I didn't mess with anything and just allowed the install plenty of time to do whatever it needed to.... Still no Outlook.
I have to say though that in the meantime I took a proper look at the latest version of the Mail app that comes with Windows 10 Build 10074 and was impressed. A huge improvement over earlier versions and i may even consider using it from time to time.
As for Office 2016 Public Preview.. I wish they had made it clear that Outlook isn't included or doesn't seem to be and installing the Preview will make any existing version of Outlook unable to run.
Seems like it's back to 2013 for moi..