There is some similarity between the two, with Rove leaning to being a more hands-on, nuts and bolts electioneer, and Gingrich leaning to being more of a sweeping sort of ideator. They're both brilliant men. Too bad Newt got so thoroughly "Quayled" by the media, but he did help them along with his own impolitic behavior.
The rats that I eavesdrop on fear Newt far more than Rove, both as an operative '08 and candidate '08.