Interestingly, ISS was one of the success stories from the original portfolio of companies in the Kleiner Perkins "Java Fund" of companies which included Marimba (which went public and eventually was acquired by BMC) and Active Software (which went public and was acquired by webMethods).
IBM has now picked up three public companies this month alone. Two weeks ago it bought FileNet Corp. for $1.6 billion. On Aug. 3, Big Blue bought MRO Software Inc. for 740 Million. MRO helps industrial companies track physical assets. In addition to these huge public acquisitions, IBM also acquired privately held SOA Insurance specialist Webify for an undisclosed (and presumably relatively small) sum.
ISS is involved in "managed security services" which protects against data theft and other problems with automated monitoring products and with technical consultants, who are absorbed by IBM Global Services. In October of 2005, IBM acquired XML gateway appliance vendor Datapower which may be a part of the overall security service portfolio.
Although MRO could hardly be considered SOA related, and ISS is only marginally SOA related, Filenet posessed workflow and content management assets which could be useful in SOA. The significant trend is that IBM has been on a software acquisition rampage which will have a significant effect on the future of software and services.