When you take snapshots of a given VM, you're presented with a highly readable diagram of all the snapshots you've taken and which one you're currently using. This removes a lot of the confusion from such a useful feature, and it makes it harder to accidentally delete or jump to the wrong snapshot. The AutoProtect function can make snapshots of a given VM on a schedule, which amounts to VMware's own version of System Restore.
Aside from the regular VMware interface, VMs can also be remotely accessed via the open source VNC protocol or shared out to other VMware Workstation users on the same network. Virtual machines can also be uploaded to or from an instance of VMware vSphere -- a neat way to make Workstation into a local staging ground for to-be-deployed machines.
In the category of "most oddly useful cool feature," there's the "capture movie" function. Audio and video output from a given VM can be piped directly to a movie file -- a great way to create demos, walkthroughs, or documentation.
VMware Workstation's main window presents you with quick shortcuts to many common tasks. Note that some, such as virtualizing a physical machine, are available only through external products.
Oracle VM VirtualBox 4.2 Right up front I'll say that VirtualBox, even in its newest incarnation, isn't a feature-for-feature match for VMware Workstation. It is, however, a very good way to get most of the core functionality of Workstation without paying the full retail price, especially if you're using the open source version. (The binary version of VirtualBox, which includes proprietary extensions such as USB 2.0 support, is free for personal use, but requires commercial licensing for professional deployment.)
The best way to distinguish the two programs is by a word I used a lot with VMware Workstation: polish. When VirtualBox has a feature also found in Workstation, most of the time it's Workstation's implementation of that feature that really shines.
Consider the VM setup process. In VirtualBox, this involves using a wizard that prompts you for which operating system you're going to be installing in the VM. However, it doesn't provide the kind of extended setup automation features that Workstation does. The wizard does set a recommended memory size for the VM and maybe a couple of other internal options, but the actual OS installation process still has to be done manually.
A new feature in VirtualBox is the ability to group VMs, even in nested groups, for the sake of organization.