:::: A Pink Floyd reunion is still possible for a one-time occasion (a good cause). Wright was an important member of the group, but not the frontman of the group (it would be not the same as "Queen touring without Freddie Mercury"). If David Gilmour, Roger Waters and Nick Mason would reunite (together with Dick Parry, Jon Carin, Guy Pratt, etc), than this can be surely determined as a Pink Floyd reunion. If Led Zeppelin would play some concerts (without John Bonham), than this will also be determined as a Led Zep reunion and so on. In theory a PF reunion is possible and in fact also in practice if David Gilmour agrees with it (and this can be the case for a one-off performance such as Live 8).