Part of the issue is now there are more things that impact performance significantly. It used to be that clockspeed was the biggest indicator, then it was clockspeed and cache, now clockspeed, cache, and cores are all being used.
AMD's naming is pretty simple, Phenom II vs. Athlon II is just L3 cache, X# is # of cores, and clockspeed is just the higher number.
Intels approach is confusing mostly because of the Core i5 750. Otherwise i7 = 4core/8thread + Turbo, i5 = 2c/4t + Turbo, and i3 = 2c/4t + no Turbo. But, of course, we have the funny i5 750 which is 4c/4t + turbo. The dual-socket thing is kinda funny, too.