This could aid developers of applications that sync small amounts of user data in implementing iCloud synchronization. The previous limit was fairly small, enough for a user preferences, and not much more.
The change was apparently made several weeks ago , but its announcement just in front of WWDC is conspicuous. Apple clearly wants developers to know that this storage limit has increased, and to implement iCloud syncing, more than ever.
The key/value store is apparently extremely easy to use and quick to sync. So this should make it easier for developers who make apps that synchronize a small, but workable, amount of data to implement iCloud in their apps.
There are lots of expectations around what Apple could be announcing at WWDC, which is 12 days away. More iCloud APIs and expanded use of Apple’s cloud syncing solution for developers are among them.