There is quite a bit of back and forth on the savings one might achieve with consolidation and virtualization, but no doubt a reduction from 60 servers to two is a monumental accomplishment (granted they were monster servers, ES7000s with 24 dual cores and a boatload of memory comparable to six standard form factor, four-socket quad-cores).
Virtualization gotchas to note
There are some aspects to virtualization that you should be aware of before you proceed with your Exchange environment -- or any server environment. Make sure you decide what you will consolidate and what you will virtualize. There is a difference (although some don't realize that). One reason for the overwhelming server sprawl is due to deployment strategies in times past that encouraged a server in every location (leading to tremendous server underutilization). Now we see that server consolidation in fewer key sites provides for better server density, higher server utilization, fewer servers to manage, less attack surface, lower costs, and the most coveted of them all: green IT.
When considering virtualization, you need to think about the method you will use. Will you virtualize your physical environment into a virtualized environment, or will you use virtualization for a disaster recovery product? So you need to think physical to virtual, virtual to virtual, physical to virtual to virtual -- it can get a bit cumbersome. You need to decide the type of virtualization software you will use (VMware's ESX and Microsoft's Hyper-V being key players these days).
You also need to know what you can and cannot virtualize. Unified Messaging server for Exchange and the Office Communications Server are two examples of servers that are not supported by Microsoft for hardware virtualization. That isn't to say they won't work, but you won't have support if there is a problem.
Other Exchange roles like the Hub Transport and Client Access Server roles are perfect for virtualization. The Mailbox role may be a bit of a debatable issue in terms of performance losses for virtualizing. On one hand, you may lose some performance off the server by putting your Mailbox servers in as a virualized box with other systems, which may be counterproductive to your goal of a high-performance Exchange environment. However, you might consider this approach if you have an extremely large mailbox environment: There is a hard limit on connections for physical Mailbox Server instances.