For those who are unaware, a rumor of Zelda Wii being the last game was brought on by not being unable to understand the difference of "series" and "saga". Rumors started on 2Chan said that Zelda Wii would be the last of the saga-- the saga the rumors are talking about is the Hero of Time saga, as the current rumor is that Zelda Wii takes place after MM when Link is an adult. So, that's where all this nonsense started- with a misunderstanding of something that's just a rumor to begin with.
Anyway, no, I don't think it'll be the last. Why? It's a huge franchise. It's right up there with Mario. Nintendo needs both Mario and Zelda. Mario is an easy series to use to get casual gamers into new fads. Zelda is more of a way to get more serious games into said fads. In my opinion, Zelda should've ended at OoT. Don't get me wrong, I loved TWW, but I feel like Aonuma is poisoning the series. That's my own opinion, though. In any case, Nintendo surely isn't going to let Zelda die anytime soon.