Google Chrome extension lets you use IE9 pinned site actions on supported sites
Microsoft has also shared how this works (and Scott Hanselman has posted an excellent how-to article), so it's possible for other browser makers to implement, too. If you're a Google Chrome user, in fact, you can install an extension (developed by an independent programmer) which adds jump list actions to a drop-down menu on the Omnibar!
Unsurprisingly called IE9 Jump List Tasks, the extension adds a green arrow to the Omnibar whenever you visit a supported site. If jump list actions are detected, clicking the arrow will display a menu like the one you see above. It's not quite as cool as being able to poke your taskbar icons, but it is a neat display of how the feature can be utilized in non-IE browsers. The extension also didn't work for me on all the sites I tried -- Twitter and Facebook lists weren't detected -- but it was still cool to see it pop up elsewhere, like on IMDb and Flixster.