ICANN has begun the process of putting delegation signer (DS) records into the root zone for those top-level domains (TLDs) that have signed their zones.  By the time the root is signed with a live key in mid-July, the root should be populated with the DS records of all of the TLDs that have signed their zones.  The process began this week with the DS records for Brazil (.br), the Czech Republic (.cz) and the United Kingdom (.uk); all three are now visible in the root zone.  Go here for a useful table showing the status of TLD deployment of DNSSEC.