Doesn't serving status page form the site itself defeat the purpose of status page? In what case would that make any sense? I am now intrigued, this is not a small thing that can get over looked.
For status other than "site is down", it's probably nice to have information on-site since I guess tumblr is about sharing easily within tumblr. But maintenance and server status needs to be both on-site (tumblr.com/status ?) and an off-site page at status.tumblr.com.
No, it does not defeat the purpose. Instead, it just lessens the effectiveness of the status page. It really depends on what tumblrs most common error scenario is. 95% of errors may manifest themselves in manners which do not affect the status of the status page.
The whole notion of "hosting" a status page is ridiculous.
You just generate it as static HTML and dump it on a bunch of free webhosters (or clouds if you want to be fancy). It's not rocket science to keep a HTML page online.
It would be reasonable to have something more sophisticated, like heroku's status page, which has both text/timestamp information and graphical representations of status. If you have an API, reporting deeper info about each part of the API is also a good idea.
It still should probably be a static page, but updated frequently and by automatic tools.
