If you are a current user of Telerik Sitefinity CMS, you may already know that Telerik has recently released Sitefinity v. 4.0. However, Sitefinity v. 4.0 does not offer any out-of-the-box support for migrating from an earlier release of Sitefinity (namely v. 3.7) to v. 4.0.
However, in order to accomplish this task, they have released a Sitefinity Migration Tool on CodePlex. The source code for the project can be downloaded from here: http://sitefinitymigration.codeplex.com/SourceControl/list/changesets
I have previously deployed numerous sites using Sitefinity v. 3.7 and attempted to migrate several of these websites using the Sitefinity Migration Tool.
Unfortunately, each and every single web site that I attempted to migrate failed miserably. Either only some of the content was migrated or the content was not migrated at all.
So where does that leave you? Basically, if you want to adopt Sitefinity v. 4.0 in the near future, it looks like you will have to start pretty much from scratch. At this point, the Sitefinity Migration Tool is simply not production-ready and will likely fail in migrations about 99.99% of the time.
If you are able to successfully migrate your v. 3.7 site, all the better for you. Otherwise, I would probably recommend sitting tight on v. 3.7 for now. If you want to leverage the capabilities of .Net 4.0, you can consider upgrading to v. 3.7 SP4 with .Net 4.0 support (if you have not already done so).
Hopefully, prior to the release of Sitefinity v. 4.0 SP1, Telerik will offer a better migration path than what they have today.