Donk, on Nov 24 2011, 08:08 AM, said:
You will need it as it has been fixed in Fusion 4.1.1 for Snow Leopard and Leopardclients. If you are only running Lion then you do not need the unlockers.
Just for completeness, I downloaded the latest Apple EULA for OS X 10.7.2 "Lion", see the extract below regarding running virtual instances, in particular 2B(iii):
2B. License from Mac App Store or on Physical Media. If you obtained a license for the Apple
Software from the Mac App Store or on Apple-branded physical media, then subject to the
terms and conditions of this License and as permitted by the Mac App Store Usage Rules set
forth in the App Store Terms and Conditions (
http://www.apple.com/legal/itunes/ww/) (“Usage
Rules”), you are granted a limited, non-transferable, non-exclusive license:
(i) to download, install, use and run for personal, non-commercial use, one (1) copy of the
Apple Software directly on each Apple-branded computer running Mac OS X Snow Leopard
or Mac OS X Snow Leopard Server (“Mac Computer”) that you own or control;
(ii) If you are a commercial enterprise or educational institution, to download, install, use and
run one (1) copy of the Apple Software for use either: (a) by a single individual on each of the
Mac Computer(s) that you own or control, or (

by multiple individuals on a single shared Mac
Computer that you own or control. For example, a single employee may use the Apple
Software on both the employee’s desktop Mac Computer and laptop Mac Computer, or
multiple students may serially use the Apple Software on a single Mac Computer located at a
resource center or library; and
(iii) to install, use and run up to two (2) additional copies or instances of the Apple Software
within virtual operating system environments on each Mac Computer you own or control that
is already running the Apple Software.
The grant set forth in Section 2B(iii) above does not permit you to use the virtualized copies
or instances of the Apple Software in connection with service bureau, time-sharing, terminal
sharing or other similar types of services
[UPDATE] I have checked the Apple EULA for OS X 10.5 "Leopard" and 10.6 "Snow Leopard" and the Server virtualisation restriction still applies, so it is ONLY 10.7 "Lion" that supports client virtualisation, and of course only in the words of Apple "for your Apple-branded computer".