@RebeccaChernoff And apart from notebook attachments, would it be possible to have CDF files embedded in blog posts? CDF files are Mathematica notebooks with some interactive functionality that can be embedded in webpages. There's a WordPress plugin for it. The
Wolram Demonstrations Project uses them too. Typically there would be a static placeholder image with a link for those who don't have the CDF plugin. Those who do could try the interactive example.