In the Dec CTP release you might see the following editing changes compared to the Sept release:

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 passwordBox.PasswordChanged += new TextChangedEventHandler(MyHandler);  BECOMES

passwordBox.PasswordChanged += new RoutedEventHandler(MyHandler);

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AutoWordSelectionProperty is moved from RichTextBox to TextBoxBase which means that this property is also available for TextBox

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RichTextbox/TextBlock/TextFlow.CreateTextPointerFromPoint renamed “GetPositionFromPoint"

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New TextElementCollection.AddRange method - It is now possible to append collections directly to other Block or Inline collections on Paragraph, Span, etc.  Previously the caller needed to iterate source collections and make individual calls to TextElementCollection.Add.

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TextRange.SelectWord removed

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TextPointer.GetLineStartPosition/IsAtLineStartPosition/GetCharacterRect no longer throw an exception when layout is dirty. - These methods will now attempt to recalculate a dirty layout instead of throwing an InvalidOperationException.

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FlowDirectionProperty exposed on Inlines – Now we can have XAML like

<Run FlowDirection=”RightToLeft”> Hello </Run>

Also when applying the FlowDirection through TextRange, keep in mind the following:

• If the textrange is empty, we apply FD to its paragraph parent.
• If the textrange is not empty,
  • If it does not cross any paragraph boundary, we apply FD to inlines in the range.
  • Else, we apply FD to all paragraphs in the range.

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All these changes have been included to better the users experience with the product and we sure that it will bring smiles to their faces :)

and yeah, Wish u all a  very Happy New Year!!