We have addressed the Microsoft.SqlServer.Server namespace conflict apparent from the first preview by moving the relevant classes under Microsoft.Data.SqlClient.Server. The relevant classes include SqlDataRecord, SqlMetaData, and classes used for User Data Types (UDTs). We are aware of limitations related to reading and writing UDTs using Microsoft.Data.SqlClient and are working on making the library as compatible as possible with UDTs.
The other major change we made in this preview was splitting out the native code into its own library when targeting .NET Framework. This fixes the issue of only being able to target x64 on .NET Framework when taking a dependency on the NuGet package. You can now target x86, x64, or AnyCPU and Microsoft.Data.SqlClient.dll will load the appropriate x86 or x64 native library dependency at runtime.
For the current list of changes in Microsoft.Data.SqlClient 1.0, please see the Release Notes.