I've been blogging about C# 4 features recently so I updated the keywords in App_Code/Extensions/CodeFormatter/CSharpFormatter.cs as follows:
protected override string Keywords
// updated on 14 June 2009 by W. Kevin Hazzard for C# 4 per:
return "abstract as base bool break byte case catch char "
+ "checked class const continue decimal default delegate do "
+ "double dynamic else enum event explicit extern false "
+ "finally fixed float for foreach from get goto group if "
+ "implicit in int interface internal into is join let lock "
+ "long namespace new null object operator orderby out "
+ "override partial params private protected public readonly "
+ "ref return sbyte sealed select set short sizeof stackalloc "
+ "static string struct switch this throw true try typeof "
+ "uint ulong unchecked unsafe ushort using value var virtual "
+ "void volatile where while yield";
You may want to do the same. Hopefully, Al or Mads will make a change to the source code base, too. Enjoy.