Rollins is remembered for managing Ronald Reagan's '84 campaign. Rollins may have managed it, but he did not "run" the incumbent president's re-election campaign, as the title might imply. The truth is that George Washington wouldn't have beaten Ronald Reagan in 1984, but Rollins deserves credit for winning 49 states (he claims in his excellent book Bare Knuckes and Back Rooms that he could have won Minnesota, too, had Nancy Reagan not diverted funds to California).
Rollins also was a co-manager for Ross Perot's disastrous campaign.
Most recently, Rollins has been a talking head on lots of cable news shows. He was also a top consultant for Katharine Harris' quixotic U.S. Senate race in Florida. After leaving the campaign, he gave numerous interviews to reporters, telling them precisely how out-of-touch she is, and how disastrous her campaign was. While this was all undoubtedly true, it's not common for an advisor to leave a campaign and then begin criticizing it.
Rollins' name brings Huckabee credibility, but that's about it. Rollins will probably make a lot of money from doing this race -- but I wouldn't over-estimate the impact he will have on the race.