For every one that has mango already and those that should be getting it soon (very soon). The web marketplace is now live. So you can browse apps and download them. It will start downloading on your phone. I've already tested it and it works like a charm.
Have fun guys.
Update: My bad... You can access it at windowsphone.com
You can also view your purchase history and reinstall the apps from there. As well as track your phone location.