(This post is more for entertainment, and purpose of discussion more than a real plea)
This trade can work beautifully for all four teams, but of course with risks involved. I'll explain why each team might be interested in doing such a trade.
There's almost absolutely no reason why the Grizzlies shouldn't do this trade. For one, it saves an immense amount of money for the organization. Only one locked up for long is Nene, but his contract is smaller than both Gay and Randolph, while posting higher PER than both of them this season. No reason for Grizzlies to be really worried about Nene's age as Randolph himself isn't a young player. They also get Jordan Crawford, a rising combo guard who's been quietly putting together a good season.
If the Wizards are going to make a trade for an above average player of Gay, might as well get the most talent possible in the small window available. The Wizards will be able to bring two big names to the team while maintaining relatively controllable cap situation because of the shorter (but larger) contract of Gasol. If the Wizards can retain their 2013 first with protection in this trade, this is a huge win in terms of talent level. The only reason why the Wizards won't do this is probably the near luxury tax numbers for a team that's been historically bad. But if the organization is willing to take the risk of going for Gay, might as well take this risk as well. The worst thing that can happen is a complete rebuild in a year when Ernie's contract expires and Ted decides to blow things up. And even by then Gasol's contract will be expiring and the rebuild can happen rather quickly. I think the downside is worth the upside for the Wizards.
Now, from all four teams Lakers will probably be getting the least. But there are reasons for the Lakers to do this trade. For one, David West is a much better fit with Howard than Gasol is. Second, they can save lots of money since West, and others coming back are on relatively shorter and smaller contracts, also helps them with flexibility down the road this season. Third, they gain depth which is crucial to surviving the season. Fourth, they gain youth in Gerald Green, Chris Singleton, and DJ Augustin. There's no reason to think that the two of Green and Singleton won't outproduce Metta World Peace in the years of their contracts. On paper the Lakers are definitely losing in overall talent, but in a season that's looking like it's lost, they might as well try to save money while finding better fits to the roster and adding depth.
The decision for the Pacers to pull this trade probably rests on whether they want to play in the upcoming free agency or not. It also depends on how they view the Randolph-Hibbert combo. I personally think it's better than West and Hibbert because while both play relatively soft for big men, while Randolph likes to bang, but also has the range to stretch the floor for Hibbert. On paper Pacers would be acquiring an upgrade on talent, but this also makes them flirt with the luxury tax in the next 3 years. Ultimately, I think the Pacers will be the reason this trade can't happen, but if we add a top 5 protected 2013 pick..? Then I think there's a real good reason for the Pacers to do this trade.