Since the new standard does not provide a backwards compatibility to the preceding standard, it will not be possible to address uniquely domains containing the characters "ss" or "ß", until all browsers support the new standard. Not to be able to address unequivocally every specific domain could damage the confidence in the DNS.
DENIC applies therefore a two-stage process for initial registration of domain names containing "ß". The official launch of the domains will be preceded by a sunrise period of three weeks, which has begun on 26 October 2010. During this time, only those domain holders, who own domains containing "ss" were able to register the pendants with "ß".
Hans-Peter Oswald
http://www.domainregistry.de/...