We’ll definitely make use of one of the big advantages of the Code-First approach and start writing our Entity classes immediately, without worrying too much about what Database Engine we’ll use.
Truth be told, we already know something about what we’ll eventually use. We won’t be adopting a NoSQL solution, as they are not supported by EF yet; we also don’t want to commit ourselves into purchasing expensive license plans, so Oracle and the commercial editions of SQL Server are most likely out of the picture as well.
This leaves us with relatively few choices: SQL Server Compact Edition, SQL Server Express, MySql, or other less-known solutions such as PostgreSql. That being said, adopting Code-First will give us the chance to postpone the call until our Data Model is ready.