They should just give them year numbers. This is the 2012 iPad. Older models are the 2011 iPad and the 2010 iPad. The system is perfectly simple to understand and has planned obsolescence.
iPhone = iPhone 2007. iPhone 3G = iPhone 2008. iPhone 3GS = iPhone 2009. iPhone 4 = iPhone 2010. iPhone 4S = iPhone 2011. "iPhone 5" = iPhone 2012.
Even if Apple were to never refer to them by those names, it's such an obvious naming convention (so far) that it's surprising that so many people are missing it.
the mistake apple made with ipad/iphone branding was not to drop the 1/2/3 numbering scheme, it was to use it in the first place.