Check https://dev.windowsphone.com/en-us/join for the details. "Offer valid 10/30/2012 12:00 AM PST through 11/7/2012 11:59 PM PST", and they still charge 99 USD, but credit back 91 in 30-60 days.
But if you prefer a much better value for money, check out the Premium Developer Program
Joined DVLUP yet? This is my DVLUP referral link