I’ve seen signs that at least one media organization has actively blocked MediaCreeper, it’s the Swedish newspaper Aftonbladet. They have almost disappeared from the toplist and latest pages, only a few hits per day.
I’ve foreseen this situation and have a solution, it’s a bit complicated, a WordPress-plugin (called “Creeper-Ping”) that acts like a proxy — it will forward each page-load to the MediaCreeper server to verify if it’s a hit/miss and serve back the banner accordingly. This plug in is still in early beta and I have it installed on my Swedish blog for testing and development purposes only, it seems like I have to spend a few hours this weekend to get it into production quality.
It’s prepared for several more sites just like MediaCreeper, as the underlying framework is going to be released as open source as soon as I bang it into shape.