<Glazblog/>

So the main problem with IE8's implementation of webslices was, from my mozillian point of view, the clickable icon appearing in the web page when the pointer hovers over a webslice:

• positioning an image like that requires the image to be a child of the body, not of the slice. It would break the layout if for instance the slice were a table and the image a direct child of that table...
• when you apply from chrome JS an XBL to an HTML element in a browser, there are severe limitations to what you can do from chrome JS; for instance, it's almost impossible to reach the properties of your bound elements
• of course, you want the icon to appear when you hover over the slice, and disappear when you leave the slice. But the icon cannot be a child of the slice, so it disappears when the pointer moves to the slice... sigh.
• XBL are unbound from HTML elements only if you apply another binding, that's a bug; -moz-binding: none has no effect

I was tired so I went to bed rather early with the feeling this was going the bad way. Simple problem, too complex to solve. Around 4am, a cat woke me up, probably chasing a bird or fighting another cat in the gardens in front of my bedroom's window. Could not sleep again so I went to my desk and after long (really long) fights with XBL and the DOM, I finally succeeded. It's a bit hacky, because I had to find a suitable workaround for each issue expressed above, but it works beautifully. The icon is clickable and that registers a new webslice in the toolbar. Finally. I can now go back to bed and sleep peacefully :-)