"Obama blows the starting whistle – who will his opponent be?"

"In a highly unusual move, Obama will be the first U.S. president in modern history to place his campaign headquarters outside of the Washington DC and suburban Virginia corridor (basing it instead in his home city of Chicago).  The president hopes that this break with recent precedent will help recapture the spirit of his hugely successful 2008 campaign as he seeks to become the first candidate in US history to raise $1 billion in presidential campaign finance."

Reuters has more.