Tumblr is at odds with itself: it encourages site customization, but the dashboard encourages a workflow which nullifies any of that effort. The problem is broader: I consume most sites through my RSS reader, which has the same effect.
I can easily imagine an RSS reader that has news items on the left, and a browser view on the right. While I speed through my RSS entries, the corresponding page is loaded up on the right. This would merge the speed and convenience of RSS, with the desire for visual identity, and the need for page views / advertising.
Tag Internet, you’re it!