Hello,
You need not be concerned.
Immunization will not be dropped, we will continue updating immunization.
However, lately there has been a change on how malware handles it's 'servers', many domains hosting malware exist only for a short time and those who exist longer are mostly hijacked websites.
Protection against malicious downloads from legit websites is handled our IE browser helper object in Spybot S&D 1.6.2.
Immunization mostly blocks the whole domain which is usually not wanted when a legit domain only has a couple malicious files for download (IE Helper will block these downloads).