I havn't been working that much with IIS 7 and not on 64 bit environments yet. Always easier to work with what you know but sometimes you just have to get out of that comfort zone and grasp the new!
IIS 7 has a very different GUI from IIS 6 and there are many changes under the hull aswell.
I was trying to install the eService Accelerator on a 64 bit environment with IIS 7 on Windows Server 2008 R2 and the example portal (Fabrikam) gave me the following error:
Could not load file or assembly 'Microsoft.Crm.Sdk' or one of its dependencies. An attempt was made to load a program wih an incorrect format.
A little digging around and checking some blogs I found the error, the app pool was set up to not support 32 bit applications. The fix is to mark the app pool, click advanced settings, and under the general section, change the "Enable 32-Bit Applications" to true. Then you can just confirm this by updating the webpage.
President, Chief Architect and co-Founder at CRM-konsulterna AB