Congratulations to the work.
It is very easy to install a fresh copy of the CTP for test. I am using ASP.NET 4 for the application.

I have run into this issue when use the default site to create a template with content:
myTemplat_Test.template is not a valid Portal Template File.

Validation Results

The element 'settings' has invalid child element 'timezone'. List of possible elements expected: 'backgroundfile, timezoneoffset, containersrc, paymentprocessor, autoaddportalalias, portalaliasmapping, hostspace, skinsrcadmin, siteloghistory, expirydate, userquota, containersrcadmin, pagequota, currency, skinsrc, hostfee'. I can  remove the time timezone element to make the template keep going to create a new child portal.

Ken,

I used the default without changing any timezone setting. I tested one more time and I got the same error.

I have a fresh install to test this issue.
I can reproduce this behavior.
But I can remove this line from The template XML file to make it work.
<timezone>Pacific Standard Time</timezone>

I have also tested this feature with another UPGRADE install(production 560>>6ctp) . It seems it is working fine with the upgraded site.