Just at the point when it seemed that the GOP would get a free pass in a competitive district, the Democrats suddenly have a strong challenger to Jon Porter in NV-3. Porter is a first-termer who has done next to nothing (other than raise about $1 m) after running a ruthlessly negative campaign in 2002 to a landslide victory (62-38). The district however is evenly divided between Ds and Rs and includes a lot of newer development ringing the Las Vegas valley so lots of first-time voters in the district.
The challenger, set to announce soon (according to local political reporter John Ralston) is Tom Gallagher, a lawyer and former gaming company executive (who worked for, among other companies, Park Place Entertainment owned by the family of Sen John Ensign (R)) who has a personal fortune of at least several million dollars. He's got next to no name recognition and as of yet no issues (other than public statements against the Patriot Act), but in a competitive district and expectations of heavy spending by Harry Reid for re-election and the presidential nominee in this swing state, there is at least hope of a pick-up here.