Adam,
Prerequisites will be achieved within a single "group task" which will be edited as a single item. Here is an example:
+ pay bills @s 2012-07-26 @r d &i 30 @f 2012-08-05:2012-07-26
@i 612a09b9-ec7c-4a13-a785-171493f06772
@j collect bills &q 1 &f 2012-08-24:2012-08-25
@j get stamps &q 1 &f 2012-08-25:2012-08-25
@j get checkbook &q 1
@j write checks (bills, stamps, checkbook) &q 2
@j mail checks (bills, stamps, checkbook, write) &q 3
The jobs (tasks within the group) are given by the @j entries and the
prerequisites are determined by the &q entries within the jobs. Here
collect bills, get stamps, and get checkbook have no prerequisites. The
first 3 are required for write checks and the first 4 for mail checks.
The individual jobs and finish dates, if any, are only shown for the
current repetition. Finish dates, by the way, have the format "date_done:date_due". Only the group task would be shown for the last
completion, if any, and any subsequent repetitions. This is illustrated below:

-Dan