I'm hearing from a number of friends and allies that they've marked the kickstart to remind them later, or are waiting for better financial circumstances like a forthcoming paycheck to back us. While I don't quite get that strategy (after all, KS doesn't charge you until we fund or don't on the 17th), I do hold out some hope for a late rush...
If money is an issue, then the reminder seems valid since you'll be looking at whether you can afford to back right before the end of the campaign. If you back earlier you run the risk of not being able to afford it when the campaign closes. If you set a reminder and back it anyway, then the campaign can get hit with a drop in pledges as people discover they really can't afford it.
If money isn't the issue, my (admittedly limited) experience is that those who set a reminder aren't sure they're going to back at all.
Personally, I just pledge my top amount up-front and be done with it for campaigns I know I'm going to back. Since I tend to track the progress of campaigns I back, I suppose I might follow LL's example at the end of the campaign if I felt very strongly about making sure it funded.
"Once you consent to some concession, you can never cancel it and put things back the way they are." - Howard Hughes