I just did an update to 1.7 and the email notifications for my forms were not sent out.
I am using WP SMTP plugin with Gmail as the email account.
After I deleted the 1.7 plugin and uploaded the 1.6.12 plugin, the email notifications were being sent out again.
Just a side note, I notice that the Gravity Forms CSS Ready Class Selector plugin is not working with 1.7 too.