If you downloaded the SharePoint 2013 Customer Preview and tried to install as a Standalone deployment, you are probably having issues.  Here's the error we're seeing...

ErrorCode:SubStatus: Service running under Network Service account in workgroup environment is not supported.

This is caused by AppFabric's Distributed Caching and can be avoided by running the PSCONFIG utility with a specific switch.  Here's how to do it...
<ul>
	<li>Open PowerShell as Administrator</li>
	<li>Type the following to change the directory...
cd 'C:\Program Files\Common Files\microsoft shared\Web Server Extensions\15\BIN'</li>
	<li> Type the following to setup your farm...
.\PSCONFIG.EXE -cmd Configdb create SkipRegisterAsDistributedCacheHost</li>
	<li>Once the configuration database is completed, re-run the SharePoint Products Configuration Wizard to complete the setup.</li>
</ul>
Enjoy SharePoint 2013 and let us know what you think!