Check this out: I just read this post from Scott Hanselman about an upcoming release from the entity framework team. This really sounds like a dream come true.
For very long time now, I had to struggle with updates to database schemas. In almost any custom software development project you have to somehow take care of such issues. I used different tools from different vendors (e.g. Schema Compare, UDB Workbench, Altova DatabaseSpy, etc.). Some proved to be more efficient, flexible or productive, but at least you get to a point that automates some of your tasks (and I guess this is seems to be one (of many) success factor).