You can purchase paid/free apps using any browser on your pc/laptop. You can view what apps history which shows what apps you have purchased and can easily re-install them with 1 click of a button. You can browse the entire apps/games marketplace without needing zune on a pc/laptop say at work or someone else's machine. There is more cool stuff there so check it out.
Mango not too far now and oh, every carrier except for telefonica in Spain has approved the mango update and it's being uploaded to microsoft's update server as I type this.