It won't happen ever. Hamilton will live out his career at McLaren. Ricciardo and Buemi are destined for Red Bull once Webber retires and Vettel eventually moves to Merc (if they are still around) or Ferrari.
Ricciardo maybe...cant see either Buemi or Algersuari as being anything other than mid-field fodder.
Also I know thats how its all planned now....but I can still see a time next year when if the RBR is again dominating that there are moves again to get LH into the car. The temptation to get two of the best drivers into the one team maybe a recognised disaster to Christian Horner but then again he is not paying the bills. Plus I can just see Bernie twisting the right arms if it looks like the series is becoming too predictable because even without team orders I dont see any of the drivers you mention ever challenging an established Vettel.
It wont be up to Mr. Horner, it will be up to Mr. Red Bull. And he's driven by marketing, and lewis is very marketable. It would be very interesting to see them together but I think I'd rather he stayed at McLaren.
Hamilton is not on Red Bull's radar if reports about Ricciardo, Buemi and Algersuari are accurate. I think it would be up to Horner given that he is the team principle of the F1 team, it's his job!
As far as Hamilton being marketable I'd question that now as he has been attracting attention of late for the wrong reasons - not for doing something well, but for making mistakes. It's human nature that the mistakes stand out more than the achievements (much like if you go into a shop that you go into nearly every day and on one particular visit you get really poor service, you remember that one visit where the service was poor and forget about the numerous time when the service was good). Vettel is set to become the youngest double champion and has pretty much dominated this season. You can't get much more marketable that that in F1 unless someone like Schumacher were to join red Bull.
The only team that Hamilton has ever mentioned in interviews about wanting to join is Ferrari but I honestly can't see that happening, at least not whilst Alonso is there (no need for a who scared who in 2007 story here, no one really cares anymore 
). Ferrari supposedly have their eye on Vettel (but so do Merc if they stick around long enough), along with numerous drivers in their young driver program and possibly Perez in the long term. Can't see there being a space for at Ferrari as I think they are going to be using Sauber as a B-team. I'm pretty confident in saying that Hamilton will be at McLaren for as long as he is in F1. If he isn't I'll eat my hat!
All idle speculation of course, trying to piece together various reports that have been doing to rounds for a while so I could be wrong but I've got as much chance of being right as anyone else on here so what the heck?! 
You are probably 75% likely to be right BUT this is F1 and I could well imagine circumstances conspiring that would see LH go to Red Bull.
Hamilton is marketable because controversy creates his own market...and whether he is doing good or bad Hamilton certainly remains a controversial figure.
Put it this way I can see a scenario where RBR might think they want him.
I can see a scenario where LH might to race for them.
And I can see a scenario where BE might want that to be the case.
If all 3 scenarios were to coalesce then this would happen. If not, then it wont, but either way I'm pretty certain this will be a talking point sometime in early summer next year.
He was no faster (or slower) than Piquet Jr. There are better drivers out there waiting to get into F1 but I guess Williams running Renault engines next year will put pressure on Williams to have a French driver, plus with the French GP looking to be resurrected MrE will be wanting a French driver on the grid.