3 Points here:
Primus will tour again. They have reunited to record a new album. Tour will follow.
But will Herb be back playing Drums? Or will it be Brain again?
Pink Floyd is all done. As far as money is concerned, they are loaded. David Gilmour within the last year donated millions (one of his castles, money and tons of his equipment for charity) . His response: I cant take it with me and I have more than enough money. Another reason they will not tour is that they have been averaging a new album like every 8-10 years. Plus there tours are very demanding and last like 3-4 years each.
Waters might be the one in need of the money. Plus, Nick Mason, while a full member, doesn't get much of the royalty money. He might be in favor as well. Richard Wright is more of a hired hand since he got ousted from the band before
The Final Cut. So, he might be interested as well. Gilmour is the best off financially, so he's the only one I could see holding out.
As for Zep, I understand without Bonham that the circle is not complete. But a drummer, even as good as Bonham, can be replaced. Jason was rumored at one point. I saw the Page and Plant tour, and while entertaining they have lost all of there mojo. I am more interested in them touring under the Led Zep name and with Jonesy on bass.
Jonesy's been touring on his own. He put out a couple of album's, and I saw him open for King Crimson. From an artistic standpoint, he's doing much better work than Page or Plant have done in their respective solo careers. AND, he put on a killer show. Seeing King Crimson after him, I actually felt sorry for them follow him. He and his band stole the show.
As for rumors of Jason Bonham filling in...just rumors. He's following down his father's path in terms of drug and drink problems, so that's not very likely. And as for their collective finances, they're all in good shape following the DVD and live album releases. I would say a tour is fairly unlikely.