I've completed my initial testing of Windows 8.1 Preview, and I'm happy to say the installation was rather straight forward, seen in video below.
As far as the actual procedure? Just be sure to chose Windows 8 64 bit as your OS for the VM, and it'll work just fine as-is, even the VMware Tools install was smooth sailing as well.
Installing and running under ESXi 5.1U1 was similar to the smooth experience with VMware Workstation 9.0.2 build-1031769 and VMware Plyaer 5.0.2 build-1031769, where 8.1 also works very well.
Here's the steps I followed.
I downloaded the file named
en_windows_8.1_preview_x64_dvd_2358761.iso from MSDN at noon eastern time today. It took about 15 minutes for the 3GB, using Chrome, and my 30Mbps downstream connection. It then took about 5 minutes to upload the 3GB file to my ESXi 5.1 Update 1 host's SSD datastore, and another 10 minutes to actually install 8.1. Nice! See also my set of screenshots that are very close to identical as far as VM setup, in the RECIPE section here.
Note that ESXi hosted 8.1 can run as a triple monitor config using Remote Desktop Connection (Workstation's built-in multimonitor support works too), nice!
Jun 27 2013 Update:
The only significant twist I noticed during the installation was the need to type in a nonsense email address and password for the login screen, so that you get offered a chance to create a local user account, if that's your preference for testing.