The short answer is no.
VMware is not....or not yet capable of supporting deployments where a virtual machine is a conglomerate of multiple hosts resources. If you could do this you probably wouldn't want to. It would require every host involved to have a perfectly synched clock cycle and spend a ton of overhead keeping track of what the others are doing and waiting for everyone to catch up. Also most software that normal users would be using doesn't support that kind of parallelization anyways. Even Oracle Databases have a limit on the number of cores, and ram it can effectively use in one machine and that could easily be served by one physical server.
Now if you are designing something interesting like Blue Waters supercomputer at the University of Illinois, then you would need a backplane similar to blade server chassis and a custom OS to take advantage of it. That means custom architecture and custom software. That huge $$$ and not accomplishable by one person.
Better forms of this sort of parallelization process for the real world would involve applications that tie other computers together to optimize performance of smaller parts of a larger process. Charm++ is one example of this. This would allow a large paralyzed processing system without a custom OS that doesn't exist as a product available on the consumer market and can utilize a set of physical hosts that are not (necessarily) under one hypervisor.
Those are really only useful for working on one giant problem space like UPS or Amazon Shipping optimizations that look at every package on every plane, train, ship, or truck, at every location and take into the account the cost of fuel, personnel available and weather to optimize a global transportation plan. (or other similarly large problem sets)
The best option for most use cases would be to create applications that are composed of separate web application and database tiers each with one or more VMs to support a load balanced workload.