Lessee... DNA... Deoxyribonucleic acid... Deoxys... I think you can figure it out from there. I can, I just can't figure out proper terminology.
If Groudon represents land, and Kyogre sea, then Rayquaza represents sky.
also, after DPP, there's 493 unique Pokemon.
Think about this. With Gen1, they added 151 Pokemon, making it... 151 unique.
Gen2 added 100, making it 251 unique.
Gen3 added 135, making it 386 unique.
Gen4 added 107, making it 493 unique.
Judging by that pattern, there will be at least 593, but more likely there will be at least 600.