Only time will tell how effective this variant of TDSS would be on 64 Bit systems, I can draw a parallel between Sandboxie and this variant ie.Sandboxie is also compatible with x64 systems but cannot exactly do what it can on x86, maybe this also applies on this variant, maybe it wouldn`t be that stealthy and difficult to clean up on x64 systems as it is on x86 ones?
OS = Windows 7 HP 64 Bit
Real-Time Protection = KAV 2011 W/max Heuristics,Threatfire level 4
On-Demand = MBAM & HMP
Keylogger Protection = KeyScrambler Personal
Browsers = IE 8 with SmartScreen enabled+SpywareBlaster,Firefox W/WOT+NS+ABP