Orrin Hatch and Richard Lugar are professional Senators. Pat's not. I'm not saying he won't run. I haven't heard one way or the other. I imagine the 2006 results might influence his decision.
And here's a trivia question for you. Who's congressional seat did Pat Robert's fill in Congress when he retired in 1981? Answer is Keith Sebelius, the current governor's father-in-law.
Keith Sebelius died in 1982. He didn't live long enough to see his son go squish and his slimy daughter-in-law get elected Governor exploiting his good name.