One late-breaking bug to be aware of:
For products using any digital delivery feature (Single File Download, Redirection, Send Stored/Generated Codes, or Bundle Other Products), if the product's Email Message field is left blank, Enable Templated Email always gets submitted as un-checked. This also affects un-checking the Product Thank-you Email Message checkbox (which actually just submits a blank Email Message with a checked Enable Templated Email).
This effectively means that the new Admin cannot disable the product-specific thank-you email message for digital products, and that editing such products in the new Admin would re-enable the product email if it had been disabled previously. You can still use our old standard Flash-based Admin to (re)disable the product email if desired.
This bug should be fixed in the next day or so, before we'd make the new Admin standard for everyone.