TUAW reports USB configuration files found in the iOS 5 beta seeded to developers last night reveal two new, unreleased iPad model identifiers labelled "iPad3,1" and "iPad3,2". Considering that existing iPad 2 models are indicated in iOS as iPad2,1 (WiFi-only model), iPad2,2 (GSM) and iPad2,3 (CDMA), the discovery seems to indicate that earlier rumors of next-generation iPad getting a universal GSM/CDMA chip were correct. If that's the case, iPad3,1 could point to the new WiFi model, with the iPad3,2 device being the one with dual GSM/CDMA capabilities.
In the same report, TUAW notes iOS 5 contains mentions of iPhone4,1 and iPhone4,2 models, though these were already spotted by Engadget in the iOS 4.3 beta code. However, the article also notes there's no mention of iPod touch 5th generation in the current iOS 5 beta, leading to speculation that a new iPhone could be announced this Fall, but not a new iPod touch. On the other hand, Apple could still insert model identifiers in future iOS 5 betas set to be seeded this summer.
Model identifiers are usually a good indication of new products to come in the next months, and they correctly pinpointed new hardware before. The iPad 3 was initially rumored to be scheduled for 2011, although Apple made it clear at the March 2 event that 2011 would be the "year of the iPad 2" and a recent report claimed certification for iPad 3 components is only starting now, for a 2012 release.