I have a tradition of submit and forget. After I submit a paper to a conference I put it aside and don't think about the paper again until we get back the decision. In recent years I have broken that strict rule by sending the submission to an archive site like ECCC but in general I don't work on or even think about a paper while the program committee does its thing. No use fretting about the paper while the committee decides so best to keep busy with other research and activities.
No such luck for this year's FOCS. Umesh explains why we have to write a 2-page follow-up a week later. Lots of bloggers have weighed in, check out Jeff and everyone he links to. My main take from Umesh's letter: Authors cannot be trusted to give the proper motivations, explanations and examples in the initial write-up. And that's a shame.
The 2-pager makes bad writing self-fulfilling. Why bother with proper motivation at all in the first stage if you get to work on it later?