Warning! This post is very old and may contain information that is no longer valid.
They will also stop feed-fetching which was a nice feature that created a Facebook like mini-feed (or FriendFeed like) on the users' homepage to follow the activities of your friends on other sites.
In short, Jaiku now is going to be pretty useless.
The announcement on the Jaikido blog says that they switched off the SMS updates because of financial reasons.
Update: Jaiku will no longer be invitation only and registration will be free for anyone.