I think I read of one in Tampa in June?
I'm in South Florida...so if anyone knows of any upcoming ones...or even any like 80s toy shows, lemme know!
If by "South Florida," you mean the Palm Beach/Ft. Lauderdale/Miami area, Miami SuperCon often has a pretty decent brony vendor/guest turnout, as does Animate!Miami. Both are at the MACC, and both are affordable if you live 'round these parts. They're more focused on sci-fi, comics, and anime than MLP, though.