Is it possible to edit a xaml icons or images in the expression design or using other tools?

Yes, you can edit XAML icons and images in Expression Blend. It has some very powerful tools to help you do so. Several third-party tools are also available. Directly editing XAML with Expression Design is not possible as of version 2, but it is possible to create new XAML elements to include in your icon using Expression Design, then merge these in with Blend.

Is it possible to import a xaml images (that e.g you have exported) in the expression designer for editing?

It is possible with Expression Design 2, but it is not pretty. You can print your XAML to PDF using a free PDF writer tool, then load it into Expression Design using the "Adobe Illustrator" selection. This gives you something relatively usable but often not as clean as the original Design document. So you should save your .design files in case you ever need to change them and re-export.

How to edit a Drawing object in Blend 2

Here are the steps I use for editing a Drawing object in Blend.

If your Drawing isn t already in a DrawingBrush resource, copy or move your Drawing s XAML into a DrawingBrush resource, for example:

<Window x:Class= ...>
  <Window.Resources>
    <DrawingBrush x:Key="Whatever">>
      <DrawingBrush.Drawing>
        ... put your drawing here ...
      </DrawingBrush.Drawing>
    </DrawingBrush>
  </Window.Resources>
</Window>

Now you can edit your Drawing like this:

1. Go to the Resources tab and find the DrawingBrush
2. Create an empty window, or find an empty area area of an existing Window/UserControl/etc
3. Drag the DrawingBrush onto the artboard in the empty area

4. Select Copy DrawingBrush to Canvas from the popup menu that appears

5. Edit the Canvas using all the normal Blend tools

6. When you done editing, select the Canvas

7. On the menu select Tools > Edit Brush Resource > Move into Source DrawingBrush

Now your Drawing XAML will be updated inside the DrawingBrush. You can move the Drawing back wherever it was, or you can choose to leave it there and use it as a DrawingBrush. (Note that <Rectangle Brush= works as well as <Image><Image.Source><DrawingImage Drawing= for most purposes)

Yes, the tool I think you re looking for is Blend. With blend you can import from Expression Design, Adobe Illustrator/Photoshop. You can edit your XAML in blend that you have exported from Design.

I cannot (and would love to be corrected) find a way to import XAML to Design for further editing. My only solution is to keep a copy of all design resources, edit them and then exported the edited version to merge into my XAML projects.

HTH