Yup. I was actually thinking about this earlier today, whether localization becomes a shorter amount of time as a series becomes higher profile. I mean, to copy TJ's post:
Red, Blue: 2 years, 7 months
Yellow, Gold, Silver: 1 year, 1 month
Emerald, FireRed, LeafGreen: 8 months
Crystal, Diamond, Pearl: 7 months
Platinum, HeartGold, SoulSilver, Black, White: 6 months
Ruby, Sapphire: 5 months
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Black 2, White 2: 3-4 months?
I mean, it's nothing more than a correlation at best, but besides Ruby, Sapphire, and one or two others, there seems to be a quickening of localization as the series progresses. Part of me wonders if Pokemon could soon be like 3D Land (10 days between Japan and US) or Skyward Sword (released in all territories within 6 days).