Sadly, my first attempt was thwarted by the message you see above you. I'm a Mac user at home, and although I knew that songs were DRM'd WMA files, I hoped I'd still be able to browse the store on my Mac. I was wrong. Not to worry - I have a seven year old Dell notebook that I keep for occasions just like this.
Unfortunately, my second attempt was thwarted too. You see, like many tech-savvy peeps, I prefer Firefox as my browser of choice. Nokia, however, seems to have entered into some form of unholy alliance with Microsoft, as you can only access the store using Internet Explorer 6 and above on an XP or Vista machine. Considering the store is still in Beta, I imagine they'll remedy this rather quickly, but it still doesn't help sell their product when they're so restrictive in who can access it.