There's a "tabify" command in Edit > Advanced > Tabify Selected Lines (and the Power Tools 2010 also provide this functionality on a per-file basis) but is there a way to do this for all code files in a solution?
ReSharper has a Clean Up command but the only half-suitable option I found there is to run formatting on all files which does more than I want (I don't want to run a complete formatting, just tabifying).