As 2.x takes longer as planned, I added the SpeechbubbleContainer and StepLabelContainer (Enumerable label) to the 1.2 branch. This code was stored somewhere on my hard-drive, is still experimental.

GreenshotPlugin/Interfaces/Drawing/Container.cs

@@ -92,6 +92,9 @@ namespace Greenshot.Plugin.Drawing {
 		bool HandleMouseMove(int x, int y);
 		bool InitContent();
 		void MakeBoundsChangeUndoable(bool allowMerge);
+		EditStatus DefaultEditMode {
+			get;
+		}
 	}
 
 	public interface ITextContainer: IDrawableContainer {

GreenshotPlugin/Interfaces/Generic.cs

@@ -75,7 +75,21 @@ namespace Greenshot.Plugin {
 	public delegate void SurfaceMessageEventHandler(object sender, SurfaceMessageEventArgs eventArgs);
 	public delegate void SurfaceElementEventHandler(object sender, SurfaceElementEventArgs eventArgs);
 	public delegate void SurfaceDrawingModeEventHandler(object sender, SurfaceDrawingModeEventArgs eventArgs);
-	public enum DrawingModes { None, Rect, Ellipse, Text, Line, Arrow, Crop, Highlight, Obfuscate, Bitmap, Path }
+	public enum DrawingModes {
+		None,
+		Rect,
+		Ellipse,
+		Text,
+		Line,
+		Arrow,
+		Crop,
+		Highlight,
+		Obfuscate,
+		Bitmap,
+		Path,
+		SpeechBubble,
+		StepLabel
+	}
 
 	/// <summary>
 	/// The interface to the Surface object, so Plugins can use it.
@@ -152,6 +166,12 @@ namespace Greenshot.Plugin {
 		void DeselectElement(IDrawableContainer container);
 		void DeselectAllElements();
 		void SelectElement(IDrawableContainer container);
+		/// <summary>
+		/// Is the supplied container "on" the surface?
+		/// </summary>
+		/// <param name="container"></param>
+		/// <returns>This returns false if the container is deleted but still in the undo stack</returns>
+		bool IsOnSurface(IDrawableContainer container);
 		void Invalidate(Rectangle rectangleToInvalidate);
 		void Invalidate();
 		bool Modified {
@@ -178,5 +198,9 @@ namespace Greenshot.Plugin {
 			get;
 			set;
 		}
+
+		LinkedList<IDrawableContainer> StepContainers {
+			get;
+		}
 	}
 }