We Use Coupons has this coming Sunday's Coupon Preview. There looks to be possibly three inserts. There will be the usual two Red Plum and Smart Source, however it is possible to also find a Smart Source BoxTops Insert. The BoxTop insert is more than likely going to be regional, but you never know if it could be you, just keep an eye out for it!
If you don't receive a BoxTop insert you should be able to order it from an online Coupon Clipping service. A couple of my favorites are:
My Coupon Hunter
The Coupon Clippers