I got into the beta, but I can only use it for my main domain, and www. I’d also like to use it for my mail server, which is on a different name. (it’s on the same IP because it’s on a NAT, but it’s a separate machine with a separate name.)
Now, unless the 90-day policy is going to change, don’t waste your time with this, but if it will open up past 90 days once you’re out of beta, then I’d be willing to put a couple of certs into active production use, albeit on small servers.
If that 90 day thing isn’t going to go away, then I’ll just leave things unencrypted.