This question has always stuck with me for a long time. On one hand, the show kept going downhill little by little since the 90's and yeah you never know which cast member or puppeteer we're going to lose next, and it would be hard to see a different actor or hear a different character voice, but on the other hand, Sesame Street is of course the longest running show on PBS Kids right now, and it would be interesting to see how many more years it's going to last, as well as what other new segments we'd see in future episodes. (If they reach 50, I would love to see a TV special, and some other special products produced for this milestone.)
Same with my parents and siblings while we were watching it. They were commenting on not only how Bob had been aging, but Gordon, Susan, and Luis as well.