OK, good to know – although there are apparently still some restrictions according to comments by other HN users.
SSL is still more expensive, though. For most small content websites (< 500-1000 visitors a day), a shared hosting is sufficient with costs of maybe around 100 USD/year. For SSL, you usually need a more expensive hosting, you have to buy a certificate (OK, available for less than 10 USD if you don't care about it's quality but need mainly browser support without an ugly warning window) and most hosters allow SSL only for one domain in a hosting.
Example:
Shared hosting with 4 WordPress blogs, SSL is active but only to access the control panel since the hoster allows SSL only for one domain. Costs incl. a cheap SSL certificate: 110 USD/year.
All 4 WordPress blogs with SSL, i.e., 4 shared hostings plus 4 cheap SSL certificates: 440 USD/year.
(And caching with a Wordpress plugin is probably no longer possible …)
StartSSL is 0 USD/year. There should be more providers like them, and if the barriers to entry ($$$$) weren't so insurmountable, I'd happily start one myself. But they do a good job, and I've used several free certs from them with no issues.
You also don't need "expensive" hosting, it just needs to support SSL which is free from a technical perspective. You no longer need a dedicated IP either.
That's only for 3 domains, not 100. 3 domains at $30/year is $10/year/domain which is no different than buying individual certs.
The multidomain cert supports up to 100 domains, but the cost is $29.88/year for the first 3 included, plus an additional $12.88/year for each additional domain.
Under this price structure, you could have 100 domains covered with one certificate, but it would cost you $1,279.24 per year for that single certificate.
3 domains at $30/year is $10/year/domain which is no different than buying individual certs.
The problem was that shared hosting plans didn't support multiple certs, forcing people with a few sites to purchase a plan for each. The multidomain cert solves this problem.
The shortage of IPv4 addresses and the horribly slow adoption of IPv6 is a big issue.
SNI works fine, but when it doesn't it fails horribly. Apache defaults to the first vhost on an IP which can result in non-SNI clients being redirected to the wrong site.
As for XP/IE7 usage, I have a client in an aerospace related industry with most of their customers still on XP/IE7.
Not anymore, unless you need to support antiquities like IE7 on Windows XP or some ancient Java-based software. SNI works just fine in other cases.