From the Twitter user standpoint, I think the change is +-0 (no noise I'm not interested in is down, but potentially interesting conversations/information by my friends is not easily discoverable any more).<p>From API standpoint, this will force API users that relied on friends_timeline call to return all updates (to, e.g. back them up, or forward somewhere) to manually request timeline for each friend, so they turned the operation from O(1) into O(N) calls, which, considering the rate limiting, is not insignificant.