I think the poo blanket will be huge. Blankets are a treasure trove of forensic evidence, as they tend to soak up everything around them. Even after months in a Florida bog, it can still offer:
*fading and wear concurrent with the rest of the matching set
*dog hair only found in the Anthony home
*matchable human detritus like hair, dander, eyelashes, etc
*fibers from the Anthony's carpet
*fibers from the Anthony's furniture
*fibers from toys still in Caylee's room, like dolls and teddy bears
*stains (juice, baby oil, etc) that match stains on the rest of the set
*possible "touch" DNA
*possible evidence of any chemicals or pharmacueticals used on the deceased.
and probably dozens more things I haven't thought of.
The laundry bag should offer much of the same evidence.