A framework method to render a partial view to a string
Render a partial view to a string to send back to an ajax request
This is not a big thing to do. Just a couple of lines of code. Check this out: http://www.tugberkugurlu.com/archive/working-with-jquery-ajax-api-on-asp-net-mvc-3-0-power-of-json-jquery-and-asp-net-mvc-partial-views
Jeremy W commented
This is doable now, just the code isn't pretty.
This would be most useful for things that don't go back to the browser like html emails