Well, if the Zelda Series ends, all you can really do is enjoy the games that were made. I think that if it were to end, it would be a shame, but Zelda does have to end sooner or later. If they just keep making more and more, there will be a point where the quality itself declines and it will become what Sonic has; living in the past of its glories, and hoping to make another great game.
But when Zelda ends, life will go on. The world won't end. I personally would still play the games over and over, but I'd still play other games too; Zelda isn't the only series I play. I've always felt that Zelda sooner or later will end, but I'm hoping it won't be for at least another ten or fifteen years. That is definitely pushing the boundaries, but it's worth hoping for.
The only thing that concerns me though is the release of the timeline. Now that we know the timeline, I don't think Nintendo can really move games around, they can place new ones in between older games in the timeline, but not switch old ones around. This may disrupt their creative process because now the public knows how things are supposed to fit. Going back on their word now would take away any credibility that Nintendo has and any official thing they release would be taken as seriously as a fan fiction.
But the thing is, Zelda is a legend for a reason. There will come a point where the legend has told everything that there is to tell; the Legend can't just continue indefinitely. Once the legend in its entirety has been unfolded, it's over. Zelda will be finished, whether it's ten years from now, or ten days, it's bound to happen.