-Changed serializing ISerializable types under partial trust to error to fix security issue
-Fixed LinqBridge collision error in .NET 2.0 by moving types to a different namespace
-Fixed JObject.Keys error when object has no items
-Added DateTimeZoneHandling to control reading and writing DateTime time zone details
-Added reader/writer specific Formatting, DateFormatHandling and DateTimeZoneHandling to JsonSerializerSettings
-Added feature of reader/writer specific settings to be set on JsonReader/JsonWriter when serializing
-Added ReadAsDate to JsonReader
-Added ReadAsString to JsonReader
-Changed JsonTextReader to automatically read ISO strings as dates
-Refactored ReadAsXXX methods and reduce code redundancy
-Removed unused JsonDateTimeSerializationMode
-Changed class converter to be resolved from contract
-Changed built in converters to be resolved once when the contract is created. Big performance gain!
-Added CustomCreationConverter
-Added IsReference to JsonContainerAttribute
-Added PreserveReferencesHandling to JsonSerializer
-Added IReferenceResolver to JsonSerializer
-Split internals of JsonSerializer into JsonSerializerWriter (serializes) and JsonSerializerReader (deserializes)
-Moved serialize stack from JsonWriter (yuck) to JsonSerializerWriter (yay)
-Added FromObject overload with JsonSerializer argument for cases when state is needed
Added support for deserializing to an anonymous type with the DeserializeAnonymousType method.
Support for reading, writing and serializing the new DateTimeOffset type.
Added IsoDateTimeConverter. Converts DateTimes and DateTimeOffsets to and from the ISO 8601 format.
Added JavaScriptDateTimeConverter. Converts DateTimes and DateTimeOffsets to and from a JavaScript date constructor.
XmlNodeConverter handles serializing and deserializing JavaScript constructors.
Ability to force XmlNodeConverter to write a value in an array. Logic is controlled by an attribute, json:Array="true".
Changes:
Dates are now serialized in a JSON complient manner, similar to ASP.NET's JavaScriptSerializer or WCF's DataContractJsonSerializer - http://weblogs.asp.net/bleroy/archive/2008/01/18/dates-and-json.aspx
Removed the AspNetAjaxDateTimeConverter.
James Newton-King