Obama and/or his staffers have mentioned Colin Powell as Secretary of State, and keeping Paulson in Treasury. I'm not sure of the wisdom of either of those choices, given that while they may be skilled in their areas of expertise, and moderate aisle-crossers by personality, they both participated in some disastrous Bush miscalculations. Robert Gates, Dick Lugar and Chuck Hagel have also been mentioned, by the Obama team, with Gates possibly intended to stay on in a National Security capacity (hopefully not as Secretary of Defense, though).
Several commentators have also mentioned Arnold Schwarzenegger. I'm not sure what our Governator would bring to the table beyond star power. He hasn't been an especially effective California executive (he hasn't been incompetent, either, but he has been arrogant and Machiavellian at times). The pundits feel Arnie has unique talents related to the environment, but I'm not entirely sure what the basis of this claim is, and I'm one of more politically engaged constituents (he's a moderate who changed his platform to conform to the prevailing attitudes in California -- politically shrewd, and I approve, but he's not exactly an environmental visionary).
The (former) Republican who Obama really could make use of is New York's Michael Bloomberg. A talented executive in his own right, Bloomberg is a moderating force who has handled the unruly New York polity generally with aplomb, and who did a pretty good job cleaning up after the mess and smoothed over the acrimony left by eight years of Giuliani. In addition to his level head and clearly proven ability to work across party lines, Bloomberg's financial expertise will also be much needed in the coming administration. Mike Bloomberg would make an excellent Treasury Secretary.
Other moderate Republicans (and ex-Republican Independents) kicking around the political landscape include former Rhode Island Senator Lincoln Chafee (now an Independent), former NY Governor George Pataki, Maine Senators Snowe and Collins, and former Connecticut Governor Lowell Weicker (also now an Independent).
However, all this media discussion about Republicans in the Cabinet raises the question: what about Democrats in the Cabinet? The big question there is: will anything be offered to Hillary Clinton or is her reputation too poisonous in terms of building a moderate coalition that includes Republicans, and if something is offered, will she accept it? So far, the only Democratic name I've heard mentioned by the broadcast media is Rahm Emanuel as a candidate for Chief of Staff. I'd like to see Bill Richardson and Wesley Clark (as Secretary of Defense) in the Cabinet, though I doubt Richardson would accept because former Cabinet members rarely go on to be President and I suspect Governor Richardson still has that possibility in mind. Ed Rendell is another popular, capable Democratic Governor who is probably not interested owing to his own career as a political executive.
Former Democratic Primary candidates are also interesting possibilities. Chris Dodd and Mike Gravel are both highly experienced politicians whose time for Presidential bids may be past, and who would make very competent Cabinet Secretaries. John Edwards, already shortlisted for VP, is likely to be considered for some position (maybe A.G.). Kucinich would be interesting, but his personality is considered sufficiently unruly, and his stands sufficiently far Left, that I doubt anyone would consider him seriously.
Our highly experienced and competent 7th District Representative, George Miller, could be interesting as a Secretary of Labor, Education or the Interior (all issues he's worked on in Congress). While I had once hoped Eliot Spitzer would be U.S.A.G. some day, he committed career suicide, leaving behind Mark Green and Andrew Cuomo to fight for the job. Cuomo won, but Mark Green has had a following in NY for a long time, and many of us were disappointed by his failure to advance farther in NY politics. I personally feel it was because Green was not enough of a machine politician, and it would be fantastic to see Mark Green involved in a Change and Hope Cabinet, even if only as an Undersecretary or an Assistant A.G.
Mainly, I'd like to see some Californians and New Yorkers involved in an Obama Cabinet. These two great states deserve to have some representation in the Cabinet, as they are first and third in the nation by population and GDP, have produced some highly competent and popular politicians, and consistently vote Democratic.