Gizmodo is floating a rumor that the name for Apple's next tablet will be iPad HD, rather than iPad 3. They base this information on alleged part listings from Griffin and Belkin.
Accessories manufacturers don't have a clue about Apple marketing plans until the very last minute. They usually get the physical specifications for new product versions in advance, so they can have products ready for launch. They also may get information about naming for product packaging, close to the release.
We are skeptical about this assumption that third-party accessory makers get information about unreleased Apple products, but share the rumor for the sake of discussion. In the past, Apple may have disclosed the designs of new products with third parties, but Apple CEO Steve Jobs said the company stopped the practice because of leaks.
Given Apple's recent propensity to name iPhone and iPad models using a numerical system, it is likely that the next iPad will follow this trend.