It looks like the user agent for AlltheWeb.com has changed. Noticed this in my web logs today (I did a trace route on the IP to make sure it wasn't a spoofed user agent, and it traces back to overture.com)...
Yahoo-VerticalCrawler-FormerWebCrawler/3.9 crawler at trd dot overture dot com; http://www.alltheweb.com/help/webmaster/crawler
