Personal names around the world
w3.org
w3.org
This has basically convinced me that you should only ever have a single (long) "Name" text input.
See also: http://www.kalzumeus.com/2010/06/17/falsehoods-programmers-b...
There's also the issue of interacting with other systems. You may want just one field but some credit card processor might want 2 etc....
Admittedly the best answer is to get a "Family Name" and a "Nick Name" (not to be confused with a user name). The big problem is convincing the management they don't need to collect first name, last name, greeting...etc
I think the problem is drawing the distinction between the questions "what is your canonical identity?" and "how should we address you?"