User blog comment:Ohmyn0/Making your wiki HTML5 compliant/@comment-6345313-20120705222210/@comment-118323-20120705232632

We have hundreds of thousands of wikis to upgrade to 1.19, so we're doing a gradual upgrade based on activity (more editors = more likely to be upgraded).

The Math extension will probably remain off unless you request it. Shoot a note to Special:Contact to be added to the ticket.

Kittens are attracted to proper HTML5 coding, so if you want more kittens -- use good code! :)