Persons or entities who lose dedicated IP hosting accounts because a provider goes out of business or fail, could have difficulty getting another one. It's not clear how this will play out.
Update: May 31
BlueHost appears to be offering "free" SSL to all webmasters, but those on shared hosting would have to purchase separate IP addresses (right now $4 a month per domain). But could this run out if IPv4 gets short? I will have to look into this in detail But some people say on Twitter that this is just a "scare" to sell more services.