The Unity view tries to incorporate elements of the virtual machine directly within the interface of the native operating system. So, icons and windows from a Windows VM would appear to run alongside those of a, say, Ubuntu operating system. For the most part, this worked during my tests, but it was slow enough that I preferred keeping the virtual machines I tested inside the single VMware client window.
There are two things holding me back from a full-on Workstation recommendation: first, (like Player) it's only available for Linux and Windows. Mac users who want to create virtual machines have to use VMware Fusion, which is currently selling for $49.99.
And price is definitely the second issue. Unlike Player, which is free, the list price for VMware Workstation is a whopping $199. That's a big chunk of change for a virtual client, no matter how many features it has. Not when there are comparably featured clients out there (including the Mac-only Fusion) with smaller (and no) price tags.
This is too bad, because VMware Workstation is a good, full-featured virtual client. If you have a virtual machine image already created, don't hesitate to pick up and run VMware Player for a free-to-use VM client.