Apple says it will not interrupt subscriptions but will let customers know of the price increase.
Although we’re changing the prices for auto-renewable In-App Purchase subscriptions, we won’t interrupt them. We’ll send an email to your subscribers in Australia, Indonesia, and Sweden shortly before their existing subscription renews to let them know of the price increase. The email also includes a link to allow customers to turn their subscription off.
In addition, we’re adding two new low-price tiers, Alternate Tier A and Alternate Tier B, for the Australian App Store. We’ll automatically update the prices for existing apps and In-App Purchases that already use the Alternate Tier A and Alternate Tier B price tiers.
We'll let you know when the change takes affect and how much the increase is. Please follow iClarified on Twitter, Facebook, Google+, or RSS for updates.