Julie Lerman's A few of the many syntax changes in VB (and Linq for SQL queries) post describes changes to LINQ to SQL parameter, entity reference, and anonymous type syntax with before and after examples. Her Stored Procs in LINQ to SQL in March CTP (The VB Version) post describes the "dramatic" syntax changes for stored procedures and the ability to drag-and-drop a stored procedure onto the LINQ to SQL modeler.
Julie includes a link to Mike Taulty's Stored Procedures in the March CTP C# post. Mike's also tracking C# changes in his "Orcas" March CTP, Finding Extension Methods, and "Orcas" March CTP - IEnumerable
Update 2/6/2007: Julie consolidated her LINQ and related updates in a LINQ and Entity Framework Resources for March Orcas CTP post to her Developer Blog. This post contains a very valuable set of links to LINQ to SQL, LINQ to DataSet, and Entity Framework resources, including Bob Beauchemin's Using stored procedures with EDM ObjectServices in the March CTP (with code) post.
Jim Wooley's Converting from VB LINQ to Orcas post gives you the changes required to conform LINQ-related VB projects from the LINQ May 2006 CTP to current Orcas standards. His Changed order of LINQ operators for VB 9 post explains why the Order By clause now comes before the Select list: To eliminate the requirement that Order By fields be members of the Select list. This change must be implented manually.
Note: Jim has joined LINQ gurus Fabrice Marguerie and Steve Eichert as a co-author of LINQ in Action for Manning Publications Co. The book will be a member of the Manning Early Access Program, so you can read the chapters as the authors write them.
The XML Team supplements its February 2, 2007 XML Features in the February CTP of Visual Studio “Orcas” post with more information on the bridge classes that let one use other System.Xml APIs over a LINQ to XML tree in The new LINQ to XML “Bridge Classes” to System.Xml. According to the authors:
LINQ to XML users can now create a tree in memory with an XmlWriter application or as the output of an XSLT transformation, validate a loaded tree against an XSD schema, use XPath 1.0 to query and XSLT 1.0 to transform the tree, and so forth.