Data Dude CTP bits can be got here, its an .img file which I a cd image, hence needs either exploded or burnt to cd before installing. I have been playing with this a lot the last few days and I am very impressed with the schema diff which I have been using to test a sample I have been working on.

SQL Server Everywhere Edition CTP bits can be got here. I have not yet played with it but I intend to, small footprint, light, fast, easy to program too, easy to deploy, support in SSMS and VS...What more can you ask for?