I'm interested in some of the questions raised about SQL Server Compact Edition, I've been using SQL Server Express edition to process a subset of data from our main dataware house server to the local desktop.
However its not easy copy data (unlike previous versions which contained DTS - MSDE) , at the moment its a matter or creating a linked server and using SELECT/INSERT method, not a great way.
Plus the restricted 4Gbyte of data, thou this doesnt apply to tempdb (does this exist in SQL Server CE??), thou you can create several databases splitting the data into each database and then create a view joining all the required data as a way around this.
I do like the sound of SQL Server CE, great for those offline client applications.