Since 2007 it's not entirely true. All directories including Main and Contrib have four subdirectories: release, testing, backports and update.
Instead of Easyurpmi you can use http://www.mandrivauser.de/smarturpmi It's already updated with the 2007.1 repos and has some nice features over Easyurpmi. But if you are using 2007.1 you only have to use them if you want to add the plf repos. Because the first time you launch the package manager tool (rpmdrake) it pops up a window asking if you want to add some mirrors. You only have to choose from the mirror list. Add both the Distribution and the update sources.
Also from the 2007.1 release you have a free update tool which automatically checks for updates. You don't have to use the command line for that.