Ok this is a good step forward. Firefox is common enough that this should make people a little more comfortable with the idea of donating to support software, which is a good thing.
Quote
Mozilla has introduced a new pilot program for Firefox developers to make a little money off add-ons they've created. Developers now have the option to place a "contribution" button on their add-on page, which lets users donate any amount they wish via PayPal.
VanDragt.com