While the late Leonard Nimoy appeared in both of J.J. Abrams' Star Trek movies as an older Spock, his co-star William Shatner is yet to show up in the Kelvin timeline. Bryan Fuller's upcoming TV series Star Trek: Discovery may be the more feasible option for Shatner to reprise his most famous role, and when Entertainment Weekly quizzed the actor about the possibility of making a cameo as Captain James T. Kirk he seemed very open to it:
"Am I up for it? I'll get up. If I said, 'I hardly think so,' that would be the beginning of negotiations. If I were asked, I might consider it".
Given that Star Trek: Discovery takes place 10 years before the original series, having the new tie-in with the old could prove challenging. With that said this is Star Trek we're talking about, and if different timelines and alternate universes can work for the films there's no reason why something similar might work for Fuller's series. We'll file this one under wait and see.
Star Trek: Discovery arrives on CBS in January 2017.