I don't actually care whether the majority of web browsers support SNI or not as I do not need to allow secure access from all browsers -- just mine will do.
For example, I just want to use https to edit my blog posts. I do not need Dreamhost to provide my website with a unique IP address just for that! I just need: a) SNI support on the Dreamhost side, b) SNI support in my browser. (b) is my business, not Dreamhost's.
I understand that Dreamhost has to concern itself with users who will see the cheaper (no unique IP address) option, pick it, then complain that "gee, it doesn't work from certain browsers". Worse, those users might train their users to just click OK on the "give your money to the bad guys" dialog, which is bad. One way to address such concerns would be to allow the SNI approach only for users who specifically request it (if you know what it is and related issues, then chances are you know what you're doing).