It will come with Meteor 1.0 (early next year). See a preview of meteor's oplog tailing https://groups.google.com/forum/#!topic/meteor-core/6GR1HKrN...
I really appreciate the work Arunoda has done on smart collections; my implementation and his package have both learned from each other. That said, there are a number of subtle race conditions involved in synchronizing queries between the oplog and the main database, and working out all the little details as carefully as possible has taken time!