SSL on a SharePoint site

Hi,

I would like to implement the SSL on our company's SharePoint server and would like to seek for some advice from you Gents/Gals

Environment

VM_A -- installed the Windows 2008 R2 - A.D. + Microsoft SQL 2008 R2 Standard Server

VM_B -- installed the Windows 2008 R2 - SharePoint 2010 Standard server

(1) I just want to follow the http://www.sharepointboost.com/blog/how-to-configure-ssl-for-a-sharepoint-web-site to install the Cert. server in on VM_A

I understand the client needs to install our VM_A's cert to their browser in order to avoid the annoying 'Trusting' information but I just wonder, if the client didn't install the cert so THE TRAFFIC IS STILL ENCRYPTED ?? 

Thanks