Probably nothing.
Rundll32.exe is the pgm that enables the various objects in dlls to be run as executables. An example: open your TM, go to processes tab, order the process name column and then rclick your system clock, click Adjust Date and Time - a new rundll32 willl open up.
From your log you can see that [NvCplDaemon], C:\WINDOWS\system32\NvCpl.dll is using rundll32 - this is your Nvidea graphics tray icon.
I could add that your hd will be showing its run lamp if your sys is using the page file, or windows is taking the chance to organise your files for smoother loading [it will do this in the background, using an organisational file in the prefetch folder that it has built after watching you work].