Apple this morning introduced iTunes 7.7.
Installing the application offers users a route to the App Store - you can browse and download applications now, but you'll need to wait until iPhone Software 2.0 ships to run them on your iPhone.
The App Store isn't automatically showing as an option when you log into the iTunes Store, though it has been showing up occassionally this morning in the main view as a menu navigation option. If it doesn't, it is very easy to get there - open up the new 'Applications' folder you'll see in your personal iTunes navigation area to the left, once in Applications select "Get more applications" using the button at the lower right. And you'll be in the App Store.
There's 500 applications to choose from now, including the much-vaunted Apple Remote app which lets you remotely control your iTunes collection or Apple TV using your iPhone or iPod tou