The 2v2 money dump requires one Protoss player and one terran or even better one zerg.
As a zerg it is your duty to play a fairly standard 2v2 opening, I usually open with my typical 13 pool 14 gas, and then drone hard and non stop.
As the protoss player it is your duty to also play your fairly standard opening, but with a few exceptions. At the 5 minute mark you will no longer be concerned with how well your economy is doing, so it is essential that you learn a good time to cut probe production, I am still tweaking with it a bit, but have found you can stop around 20, and have both geysers mining full gas.
You must also keep in mind that at the 5 minute mark, you are running into a timing window of an attack by your opponents, so it is essential that you have a minimum of 4 warpgates up and ready by around that time, cutting probe production if you need to to make sure you have the production buildings to do so.
The 5 minute mark is particularly important for both players, as the zerg you want to have your metabolic boost and lair paid for and started, as well as have around 500 minerals and 100 gas to send to your ally IMMEDIATELY.
This will allow your ally to warp in a good handful of units right away while you continue to drone.
After the 5 minute mark your styles change.
Zerg will continue to drone, until fully saturated at their main, and then some, as well as spreading overlords, and holding watch towers with a few zerglings. Zerg your job is too spread vision, and keep an eye out for enemy attacks.
To do this you will need to get overlord speed fairly quickly, as well as spread creep. Zerg it is also your duty to sack overlords if need be to get information, as well as be ready to make overseers for detect.
Protoss your job is to build gateway units, stalkers specifically as well get either dakrshrine tech or robo. You will also be in charge of defending your zerg ally, and securing expansions for them, the faster you can defend a natural for them, the more effective your build will be.
It is your job to spend the money zerg will be feeding you, and there will be a lot.
Protoss you will also be getting the double (maybe even triple) forge and get constant upgrades and most importantly blink tech.
Once blink tech finishes you can start getting aggressive.
Blink tech is your next most important timing, once blink tech has finished zerg can use their extended sight via creep, overlords and watch towers to spot for stalkers, find weaknesses in their opponents base, and blink up groups of stalkers for harassment and intense damage. making sure not to over commit and just blink out whenever need be.
This is also a good time for protoss to spread pylons and warp in Dark Templars for additional harassment and map control if they choose that route.
During these harassment attacks and pushes protoss does, it is important that zerg keeps an eye out for taking additional expansions while still maintaining the money flow to protoss. Choose expansions that are closest to your main bases, and fall most directly in line with the attack path protoss chooses. As always keep droning, keep making overlords, keep spreading the vision and keep feeding protoss your funds.
The strengths of this build are as follows:
You are splitting up your roles, less stress on both players, means they can focus directly only on a couple of things, and get better at them, it's a lot easier to make lots of units, and upgrades when you don't have to worry about probes or expanding.
Protoss should have a higher army value than his opponents even if at the same food, because he does not need the probes.
You can tech faster, and macro up armies much faster than your opponents both playing standard, how awesome is a +2/+2 15 warpgate push at the 12 minute mark?
Faster tech, bigger army, REALLY easy to do, all in all it's a pretty solid way to win a ton of games in the diamond and lower leagues.
There are some weaknesses to it though.
You are relying HEAVILY on your ally to do their role. If protoss can't macro worth a crap, or misses his tech timings, then the whole build falls apart, same goes if zerg isn't making drones, forgets to keep feeding money on a regular basis, doesn't have the lair up to get detect, doesn't expand or has poor map control. Everything will fall apart entirely if your ally is not doing their job properly you are 100% reliant on the other to do their job.
This build is particular weak to a double zerg team as your opening can't really defend too well again a double zerg rush, whether it be lings or roaches, so while I know it can work against ZZ there is some tweaking involved in defending against it.
That being said, it's fairly weak to ALL really fast low tech rushes, which is why it's so important that zerg have their spawning pool and metabolic boost up, as have a forward scout to see incoming units, as well as protoss NEEDS to have their production buildings up and finished by the 5 minute mark so they can instantly warp in the units they will need to defend a really early push, zerg can help a little bit with some zergling production but if protoss is not ready for the push, there isn't much you can do to stop them from running you over.
The other weakness is that even after the 5 minute mark, you wont REALLY be able to kick into full power until zerg can take a second base, so you have the option of risking a fairly early nat in order to get that money flowing faster or wait for protoss to be able to defend your expansion and then take your expansion when things are safer. Either case the faster you can take and defend your second the better off you will be. Once the second base is up and fully saturated, protoss will have more money than he can spend, and zerg can expand again almost instantly.
It's actually a really fun style of play and has been tested and worked plenty of times with a 4:1 win ratio on the ladder last night in the high end platinum league with one gold zerg and one silver protoss.
Give it a shot and post some replays or some experiences you had with it, I'll try to get some replays up later on.