The caterpillar infestation is Eastern Tent, not Gypsy Moth. The Eastern Tent Caterpillar mainly feeds on fruit trees, usually targeting wild or black cherry trees. Sometimes defoliation by the caterpillars can cause a decline in the trees' health, but they don't usually do permanent damage. More commonly, the concern is the nuisance factor, with caterpillars crawling on non-host plants, houses and, seemingly, everywhere. The caterpillar population will likely almost disappear soon and may or may not reoccur next spring.
According to news reports, Mark Fallon of the Briar Bush Nature Center says the caterpillars "are really not a dangerous insect. They're not extremely destructive. They rarely kill the trees that they're eating. And they're incredibly important to birds."