Hillary as Secretary of State
While I love Hillary (hell, I loved Hillary before Hillary was cool!) and think she's brilliant and would be a fantastic Secretary of State, I'm not at all enthused by the possibility of Obama tapping her for this position. The same goes for John Kerry. I don't want the Senate to be weakened by defections to the Cabinet - particularly Kerry and Clinton who have both been very effective Senators for their states and have done great work in the Senate. Also, in Kerry's case, with Ted Kennedy's condition, who knows what's going to happen when. I think Kerry would be perfect to take over Biden's position as Head of the Senate Foreign Relations Committee.
My choice for Secretary of State: New Mexico Governor Bill Richardson for a variety of reasons: he was my favorite of the initial candidates for the nomination even though I knew he wouldn't get it, he's a Governor not a Senator, he already has diplomatic experience having served as US Ambassador to the UN during the Clinton Administration, and - yes - he's Hispanic.
I would love to see Richardson be the first Hispanic Secretary of State. Obama brings the promise of diversity and the Hispanics overwhelmingly supported him. Now, this is important, I don't want him to pick Richardson because he's Hispanic - I want him to pick Richardson because i really believe he's qualified and it wouldn't weaken the Senate. The fact that he's Hispanic is a happy bonus!