We see the MVC programming model as strong candidate and it's helping us in creating more usable interfaces in the product.
Still, we invest a lot of effort in maintaining compatibility for existing functionality and I'm venturing a guess that the web forms programming model will stick around for a long time to come.
The next release will be called EPiServer CMS 6, available early next year. Our new administrative interfaces will be based on MVC, templates and existing UI will be based on WebForms. Since there is a lot of interest in MVC for template development we will look into that as well in coming versions, but will we not adandon WebForms.
Out of curiosity I'm wondering why EPiServer is choosing to implement two programming models for R3, MVC and WebForms.... Any comments?