First off you will need to plan for the migration of any service accounts that are in use, not only for SQL Server but for any other service that is using a domain specific account. If the new domain will have a trust to the old one this should help ease that transition, but it will still need to be planned and eventually implemented.

Other than service accounts and actually migrating the server into the new domain (and changing any TCP/IP service information to reflect the change) your other dependencies will depend on what you are hosting. You will need to check each of the databases you are hosting and identify what needs to be done if anything for the application they support to continue to function properly once the server moves over into the new domain.