An alert neighbor reported a sighting of a large yellow thing on the Fratelli's site at 19th & Madison. The Cow Mural there has been a neighborhood attractions for 20+ years, but the site has had a development permit since 2002. Developer Val Thomas noted (6/2/08):
I believe we are at last going to proceed with the project as apartments. Some redesign of the internal structure will be necessary, but the exterior should remain essentially the same. We hope to begin demolition of the building within the next couple of weeks.
The bulldozer suggests that demolition is imminent, so you'd better go admire the cows while you can. After years of being spared by street artists, they've been tagged recently.
You can read the history of the art project, and see the cows in their native state, in this blog post.
Details of the building project are at this old website, and (along with all the other developments) are now being documented on the new Madison Development Google Map.