Well, we all know what "Soon" means when a game developer says it.
But a news post on a popular WoW News site claims that we'll be playing the beta in less than a month's time.
If you're interested and haven't, I recommend you take this opportunity to create a battle.net account and update your Beta Profile (found under the Account button at the top). You have to download a quick app that sends your computer specs to Blizzard. We're not sure how they select it, but they likely want a wide variety of computers to see how well things run. Luck is obviously very heavily involved.
Anywho, invites will be going out most likely a few days after August 1st, according to the news post. And while things can always be delayed, MMO-Champ has proved to be very accurate on these kinds of things before.