Object still renders in a frame and you have no DOM access to "data." What developers should have been given years ago is a way to include snippets with a simple tag. Even if this tag had domain sandbox restrictions it would be pretty useful to compartmentalize features, improve maintenance and take advantage of browser caching.
I know there are plenty of good jquery plugins that do this and lots of server side scripts, but there is no good reason to not support such a tag. IMO its a good question "Why no client-side include tag?"
If you like jquery here is a good client side include script: http://bit.ly/vrd9
Cheers