A lot of the games that Nintendo produced last generation (SSBB, Mario Kart, Zelda WW, Metroid Prime) are still the games that I go back to, even today. At the time, I enjoyed games like Ratchet and Clank, Devil May Cry, Splinter Cell, or Grand Theft Auto. The latter list of games were great games. I enjoyed them at the time. Now, their "timeless status" has been marred. They have sequels that pretty much set in stone the fact that I will never play them again.
Nintendo's games aren't like that. I can go back and play SMB3 and still have a unique experience with SMW. Then, I'd have a totally different experience with SM64. And Sunshine and Galaxy are different and unique experiences, too. Look at your Uncharted's, your Gears of War's, or your Call of Duty's. Great games, but their shine dulls a whole lot faster. I've already forgotten about Drake's Fortune because now I'm Among Thieves. I may never play CoD4 again because MW2 has taken the spotlight.
Cookie cutter sequels can be released every year or two. What Nintendo is trying to bring to the market is much bigger than that. That's why they take longer to produce.
in my opinion.
