Hi folks,
I wrote about this specific feature in Exchange Server 2007 SP3 on top of Windows Server 2008 or 2008 R2 a few weeks ago at MSExchange.org http://www.msexchange.org/articles_tutorials/exchange-server-2007/management-administration/deploying-exchange-server-2007-service-pack3.html.
However the MSExchange team has just released a note stating that the same procedure is also valid for Exchange Server 2010, that is really cool and it will save a lot of time of your help desk team.
Read more at source: http://msexchangeteam.com/archive/2010/10/06/456520.aspx
Cheers,
Anderson Patricio
http://msmvps.org/Blog/AndersonPatricio
http://www.andersonpatricio.org
Twitter: @apatricio