John Gruber’s first thoughts on Apple’s announcements:
Messages is the most-used app on iOS, so it makes sense for Apple to spend a lot of time and attention on it. With the bigger emoji, stickers, and “bubble effects”, it’s clear that a lot of Apple’s work went into making Messages just plain fun. But the new extension APIs that allow for “iMessage Apps” strike me as turning iMessage into a genuine platform. One way to think about it is as an effort to move away from sharing plain text (and often ugly, unreadable) URLs that open in Safari and instead exchange software “objects” that are usable right there in the message thread.
Looks like a lot of eye candy to me, but most people need and want a little glitter in their lives.