Yes. The CSK and GCN do not include a built-in ecommerce module (yet?). But I don't think you could say that IBSPortal and DotNetNuke's core architecture and design are exactly focused on ecommerce directly. It just happens that there are ecommerce modules available for those products, and no one has made one for the CSK (that I know of).
Now... that excludes the IBS Store, which is distinctly different from the IBS Portal. The IBS Store was promarily an ecommerce app, and uses the same core design as the IBS Portal. But if I understand the evolution correctly, the ecommerce portions of the IBS Store are layered on top of the core IBS architecture, but are not a part of the core architecture itself.
There is nothing in the CSK/GCN architecture or design that would preclude ecommerce modules being layered on the core architecture, but it also has little existing support in the framework. But CSK/GCN are not targeted at commerce sites, they are targeted at community sites. But if your community sells stuff too... an ecommerce module may be a good addition, but I don't think the core architecture needs to directly implement ecommerce components.
Stephen M. Redd
http://www.reddnet.net