I assume you are talking about the recent trend in North America for 
Gold plated Pads.  This process hsa been around in the UK for about 
five years. The exact specification is 0.05 microns of Gold over 
5 microns Nickel.  According to the literature, the gold layer is too 
thin to allow brittle intermetallics to form.  The main advantages of 
Gold over nickel are that it produces a very flat surface which is 
excellent for fine pitch,  Gold is highly reflective making it ideal 
for machine vision systems,  it gives a highly solderable surface that 
is resistant to corrosion and therefore has a longer shelf life than 
that of simple tin/lead finish.
At SMI in San Jose this year I noted that several US Board Vendors have 
begun to offer this finish.  Supposedly there is only a nominal price 
differential due to the extremely small quantity of Gold deposited.

If you require further information please E-mail me and I can suggest 
vendors.

Martin Kennett - [log in to unmask],  
Design Engineer, SED Systems Inc, Saskatoon, Canada.