Mount points drive? Isn't it single point of failure?

if I be using mount points with my high availability enviornment with cluster on windows 2003 and SQL server 2005 with one drive letter. Isn't it single point of failure for my all mount points? i.e. I got G: drive (sure enough drive letters are used got only one for mount points now) mapped and has multiple mount points (data, log, etc) under G:? What happen if the G: drive is unavailable? Isn't it single point of failure?