Living in NH, you are trained to start thinking of "well that Presidential race is over, what's next". While I think its silly for candidates to be have 4-years campaigns, it helps to see what might happen in the first term of the Obama presidency in terms of where the potential candidates for the Presidency are doing.
2012
The GOP doesn't have a strong bench and I think it gets weaker with the economic crisis. The GOP purists want Governors who don't raise taxes EVER. That would probably mean a great majority of the 21 Republican governors would not make the grade as potential candidates. Only potential candidates would be Sarah Palin and Bobby Jindahl.
As for the Washington Republicans, I don't think that McConnell or Bohner would capture anyone's imagination. The only Republican I can think of that might be able to have some momentum as a potential Presidential bid would be Tom Coburn (OK)
So if there are 3 pools of candidates and there is a dirth of both state-wide and Washington based candidates then presumably the last pool of candidates will most likely be the Republican candidate for Pres. That would include current promoted (self-promoted?) savior Newt Gingrich, Mitt Romney, Mike Huckabee.
So for 2012, I would expect Mitt Romney, Mike Huckabee, Sarah Palin and Newt Gingrich to fight it out for nomination. Those 4 must go in 2012 otherwise their chances of going at a later date are essentially closed. I think Jindahl teases the Republicans, but stays out rather than go against the Obama machine. Evangelicals (Theopublicans) would go for Huckabee and Palin. Business Republicans might move to Romney and Gingrich. But overall I think its a weak field and with no Washington Republicans running for Pres, it might be fairly easy for Obama to get most of what he wants in Washington without Presidential grandstanders
2016 (Dems only)
Eight years out and assuming both a successful Obama presidency, the question who would be the Dem Pres candiate. At the moment it comes down to 3; Hillary Clinton (68 years old), Joe Biden (74) and Rahm Emmanuel (57). As Obama chose a VP candidate almost 20 years older than himself it seems that its POSSIBLE that 2016 would be a year much like 2008 with a wide open race. However, Emmanuel might be the logical heir apparent and it already appears to me that he will be a visible chief-of-staff.
One thing that this Presidential race has taught us is that you must have a constituency that goes beyond a single state and it becomes less important to be a legislator than to have a network of volunteers and contributors.