Compared to the regular Firefox, there aren't any extra features (other than features that will reach the regular version in a few weeks, since Dev Edition is a

Compared to the regular Firefox, there aren't any extra features (other than features that will reach the regular version in a few weeks, since Dev Edition is an alpha/beta of the next release). It's just a branding thing, a few extras by default, and a separate browser profile (might come in handy too).