It is hard enough to keep up with all the stuff coming out of Microsoft for developers. Although I don't think there will be rush to upgrade to the newly released SQL 2008, the case for .Net 3.5 SP1 and Visual Studio 2008 SP1 is different. ASP.NET Dynamic Data, Script Combining and AJAX History alone are features that make it almost irrestible to upgrade the .Net Framework and the tool used to program against it.
Another common problem for those already leveraging AJAX is the management of history points. With the promise of better interactivity and UI feedback with reduced flickering, AJAX raised a problem of its own: complexity to restore navigation history and viewstate with the use of the back and forward buttons in the browser without. The latest Service Pack for the framework introduces AJAX Browser History, a feature that will help the developer control navigation within an application that uses AJAX. DNN's modularity will certainly benefit, by enabling module developers to encapsulate the history points logic into their modules. Although it is too early to be certain about architectural impact on the DNN Core (keep in mind the DNN Core is still using .net 2.0 libraries), I suspect an implementation of a core service that unifies access to this feature to avoid code duplication might be a nice addition.
The best place to start learning about all the features available in these Service Packs is of course the Asp.net site. Videos, forums and other materials are already available so jump now to the downloads page to find more about the .Net 3.5 SP1 and Visual Studio 2008 SP1