AT&T has announced that as of June 7 – the same day that Apple is set to unveil their new iPhone – that they’ll be eliminating their unlimited data plan. Under their current plan, unlimited data is $30, but soon, $15 per month will get you 200 megabytes, while two gigabytes will be $25, with $10 per each additional gig. If you go over, it’ll cost you, probably a lot. While AT&T is spinning it as something that will save customers money, this is potentially bad news for anyone with a smart phone and could have some ramifications for apps like Internet radio service Pandora.

Pandora has taken off as the Internet radio application of choice, with many using it as their go-to mobile music app. ZDNet found that a typical user that streams 90 minutes of music a day is about 2.6 gigabytes of usage per month. And that’s just for Pandora, not watching YouTube, uploading photos to Facebook, or anything else.

Under AT&T’s new data plan, his Pandora usage would take him about 600 megabytes over the 2-gigabytes-for-$25 Data Pro plan. For another $10, he’ll get 1 more gigabyte of data – bringing his total to $35 per month, or $5 more than he pays now. Who knows what will happen if he streams for a weekend road trip?

What it comes down to is that once people have to pay for a “free” app, they might scale back their usage or just drop it all together. The music industry’s best known grumpy old man, Bob Lefsetz is calling it the “the death of Pandora,” and it’s not just Pandora, as the future of music seems to be gravitating towards the cloud-based subscription model with your music library streaming. “Customers are getting a good deal, and if they can understand their usage, they can save some money,” AT&T’s head of consumer business Ralph de la Vega said in an interview. The casual user will save money, but what’s a casual user these days? The silver lining is that any users currently on the $30 unlimited plan can stay on it, including when they renew their contract.