One of the minor announcements at MIX '07 was Dynamic Data Controls, part of the ASP.NET Futures release. It's like Rails for ASP.NET, which is very welcome. I recommend checking out the video if you aren't familiar with Rails. Essentially, it turns the URL into the command, so http://www.example.com/Tasks/List.aspx shows a list of tasks.
If you're looking to make something like this now, take a look at SubSonic. The new version create classes that work very well with the DataSource objects.
Brian Dougherty makes a point that it's not practical because there's no enterprise-level features like security. I'll guess that a lot of those concerns will be addressed by the time Dynamic Data Controls releases by using something that already exists in the ASP.NET world in some way. Rails seems to be the model and it doesn't have a lot of these enterprise level features either.
The video shows how easy it is to make an ugly GridView / DetailsView / FormView page for a table in the database. I don't think it's practical because it's way too ugly. Even the ability to create the control and attach the Dynamic Data Control as an extender is too limiting. Does anyone else agree that the data controls aren't suitable for a site made for a client? They require so much work, it often seems easier to use a stupid Repeater.