The Congressional Quarterly has some observations about Ohio's 15th district:
Seven-term incumbent Pryce faces her most serious challenge yet in a re-election bid. Her opponent will be Mary Jo Kilroy, a commissioner in Franklin County, which includes the city of Columbus. Neither has a primary opponent....
...But a serious challenge from a well-known candidate such as Kilroy appeared a matter of time in a district where traditional Republican leanings have weakened. Voters in the 15th District favored President Bush over Democrat John Kerry by just 1 percentage point in 2004.
CQ rates the general election contest as Republican Favored.