Exactly: the
VPLayer command. Sorry, don't know if it's available in 2010 with overrides as well, in 2008 it only has the freeze/thaw per layer, in 2011 you can change colour, linetype, etc. Notice it asks you to which VP's you need to apply each change - one of the options is ALL.
You need to ensure you're on a PS tab (i.e. TILEMODE=0 ). Then perform the changes through VPLayer's command-line options. This you could easily save into a SCR file (a normal text file containing all the keystrokes you'd have typed in the AutoCAD command line). Then you can run this SCR on multiple DWGs by sending it through ScriptPro/AutoScript/other.
Otherwise some lisp and layer states might also solve your issue.