(this topic is a little old but here is my 2 cents)
Yu-gi-oh won't die out for awhile...as one of the Pokemon fans left out there I will say--yes, it will die down like Pokemon, something new always comes along (like when Yu-gi-oh took Pokemon's place) But I think it is safe to say that now, Yu-gi-oh is at its peak (like Pokemon when the First Movie came out in 99.) Pokemon still has fans but what I notice is it's the kids that lose interest in the shows/games and the people that will always like it are older. Considering a great deal of Yu-gi-oh fans I know are 15+ in age, it will be popular for awhile--the kids always will lose interest but the true fans will be there. Who knows maybe it will get more popular....to the level of popularity Pokemon was which can be kinda a bad thing (you know how it was, kids going crazy everywhere to get cards, Parents fighting over toys at Christmas..., pulling knives on each other for cards, and other crazy-fan behavior..)