Because that's the same as electing an African-American to the White House for the first time in history.
We know that's not Karl Rove. By the time our mobile phone camera focused, we missed him.
But anyway. McCain concedes. This is really happening!
Even some of the Republican faithful are applauding Obama as McCain makes a genuinely sincere message of congratulation to the Democratic candidate. Fair dues. The two sides of the Republican party, there.
[update] Fox News report that President Bush has called Barack Obama to congratulate him on becoming president. They're also claiming that no Republican supporters at the McCain speech booed the announcement of Obama becoming president. That's certainly not what we heard.