SaaS is not only a buzzword but a real solution which is rapidly going Mainstream.(Read previous posts: Even Sap is offering SaaS ERP, Future Applications SaaS or Traditional, SaaS is Going Mainstream).
IBM's acquisition of Cast Iron is another indication of SaaS importance.
IBM is a leading Integration vendor. IBM's integration solutions are branded WebSphere, e.g. WebSphere Application Server, WebSphere message Broker, WebSphere Process Server, WebSphere MQ etc.
IBM's integration solutions address many integration needs and patterns; however it seems that none of them address properly integration of SaaS applications with Data Center applications as well as integration of a SaaS service in one Cloud with another SaaS service in another Cloud.
On the other hand Cast Iron's OmniConnect middleware was built for integrating SaaS and Data Center applications as well as integration of SaaS applications located in different Clouds. It includes a rich set of APIs for many SaaS applications e.g. SalesForce.com, NetSuite, Google etc.
Cast Iron's partners include Microsoft with its Azure platform, Amazon's Elastic Computing Cloud (EC2) and Google with its Google Apps.
OmniConnect supports three types of integration solutions: UI Mashups, Process Integration and Data Migration from Legacy applications to SaaS.
IBM acquired Cast Iron in order to preserve its Integration Market leadership.IBM challenge is as usual, integrating different acquired and sometimes overlapping integration products to coherent solution beyond branding it as WebSphere (WebSphere OmniConnect in this case?) and clearly defining the right product for each type of integration style.Even if it will succeed in addressing this challenge, I doubt if its sales people will offer the right product to a customer. This conclusion is applicable to other Mega Vendors as well.Therefore I always recommend usage of Independent Consultant's services (read my post Choosing a SOA Consultant). BPM is a good example of IBM's challenge.OmniConnect is capable of addressing some aspects of this topic. Currently IBM's BPM portfolio includes: WebSphere Process Server developed in house as well acquisition of Netfile and Lombardy.