Its interesting that people freak out about the $100 fee when Valve does it help weed out the troll entries. Both Apple and Microsoft have similar fees. Microsoft has a $99 fee for getting your games XNA games reviewed/published on the Apphub. Apple has a $99 for getting a developer account. Its the cost of entry if you want to use those services.
There is nothing at all stopping a person from self-publishing or using one of the other Digital distribution services.