According to the Apple Insider. The apple store now has a browser preview function builtin. The article states:

Apple this week expanded its browser-based iTunes Preview, now allowing users to view information on software within the App Store without ever launching iTunes.

Web site links to the iTunes Preview page can be obtained by choosing the "Copy Link" option within the iTunes application. The URL then takes users to an Apple-hosted site that provides a description, price and screenshots of any application on the App Store for the iPhone and iPod touch.

This is fantastic news. I can't count how many times someone has sent me an iTunes app link and the link has gone to the front page of iTunes. Let's try it out together, here's a sample link to see if it works for you.

http://itunes.apple.com/us/app/world-warcraft-mobile-armory/id321057000?mt=8

When viewing the App in the App Store you will see a drop down on the left side, click it and you will see the preview link option.