Dog sniffs have traditionally not been considered "searches," (see United States v. Place, 462 U.S. 696 (1983); City of Indianapolis v. Edmond, 531 U.S. 32 (2000); and Illinois v. Caballes, 543 U.S. 405 (2005)) but those cases dealt with cars or luggage, when the expectation of privacy was less. In Jardines, the dog sniff was at the front door of a home, within the home's curtilage, and where the expectation of privacy was greater. I suspect that the court will rely on the holding of Kyllo v. United States, 533 U.S. 27 (2001), where Justice Scalia (writing for the majority) said that:
We think that obtaining by sense-enhancing technology any information regarding the interior of the home that could not otherwise have been obtained without physical "intrusion into a constitutionally protected area," Silverman, 365 U. S., at 512, constitutes a search--at least where (as here) the technology in question is not in general public use.I think we're also likely to see some discussion of trespass similar to that in United States v. Jones, 565 US ___ (2012). Either way, I think the Court will come down on the side of Joelis Jardines and affirm the Florida Supreme Court's ruling.