When should you use Data Providers?

You have several applications that have been built using older versions of ADO.NET. Your development team is not very familiar with the EF and is still in the learning process. Your CTO has decided that everything should be ported to the newest version of the .NET Framework and all data access should use the EF.

Would using the Entity providers help facilitate the transition?
Is the decision to move all code to the EF a sound decision?
Should you employ any existing operations as asynchronous?