Plant has been a solo star for 25 years, and he likes his independence. He is free to do whatever he wants, something that has been particularly obvious since he liberated himself from nightly Zeppelin-heavy set lists with Jimmy Page in 1998. Read the liner notes he prepared for his own compilation Sixty-Six to Timbuktu for his own most earnest thoughts on collaborating with all sorts of folks throughout his career as a singer.
He loved collaborating in Led Zeppelin for so long because the personalities involved meshed so well together. Take away any one element, and it is incomplete. He moved on to do things so unlike Led Zeppelin after John Bonham was taken away. Despite the loss of his friend, Plant was eventually able to enjoy making music again. He even came to terms with the music of Led Zeppelin and performed many of those classic tunes again, exploring and reintrepreting the songs always with the intent of keeping it interesting.
Further, it could be argued that the present day is another creative peak in his career. He is on a Fats Domino tribute album with a gospel choir. He has an album coming out with Alison Krauss and will probably tour with her to support it. After that, he and the Strange Sensation will have another album of their own to release and to promote. Plus, he must have other things in the pipeline. So many different projects all from one man at age 59; that is commendable. His passion for music is clear.
John Paul Jones, as discussed earlier, is doing a lot of different things, including a little overlap in musical tastes with Robert Plant. Jones has been fine-tuning his acoustic side and playing many stringed instruments with a number of different bands who know who he is and respect that and pay homage to him. To Jones, however, every assembly of music is -- as the name of a touring outfit that involved him a few years ago suggested -- a mutual admiration society. With him, too, a passion for music is obvious.
At this point in their careers, would Plant and Jones ever give that freedom up permanently? No. They enjoy their respective freedoms too much. So, the point I am trying to make here is this: If there is a Led Zeppelin press conference on Wednesday, prepare yourself for the eventuality that it could mean a brief reunion. However, do not kid yourself by thinking it will outlast its expiration time of one single concert. The shelf life of any reunion coming up is very limited. They don't call it "one night only" for nothing!