Linked above is the 2012 schedule for K12online's 'Learn Share Remix' online conferences. Over a period of about three weeks upwards of 20 online conferences are offered.
To respond to the question 'does this benefit a teacher's professional development?' one must begin by admitting that any time two or more teachers are able to connect and discuss a topic with shared interests everyone involved comes out a winner. Having the opportunity to enter into the thought process of another person in a similar situation to you is simply invaluable, as it offers you so much insight into your own decision making moving forward. Often this style of interaction is found inside a place of work, a school for example, and is most of the time face to face.
What makes these online conferences even better than face to face interaction is that it offers teachers and other styles of professional educators the chance to interact with teachers etc. from other regions. Thus, achieving understanding of different points of view. It's really just too perfect.
Much like most things on the internet in 2012, the service provided by K12online is free, which simply adds to it's wonder.