One of the best feature that every WP programmer should know is the ability to schedule his posts in WordPress. This feature can do more then letting you schedule your post to publish at a certain time.
BUT: there is one caveat using the future
posts display - there is no valid DATE
field to sort on as the date for those future
posts is not yet SET
.
You could try however with orderby=ID
/ orderby=modified
and order=ASC
(of course, assuming the sequence in your future posts by ID is the same sequence as their future dates).