The "official announcement" won’t be made until noon today, but sources say New York Gov. David Paterson picked Rep. Kirsten Gillibrand to fill Hillary Clinton’s Senate seat. And, according to sources, Gillibrand has already accepted, though the representative is keeping her lips sealed.

"It’s going to be some big shoes to fill for anyone that’s being considered," Gillibrand told Albany’s Times Union as she arrived at the airport Thursday.

Now, you’re probably wondering why, exactly, Paterson chose this relatively obscure 42-year-old mother of two from upstate New York for a very high-profile seat. This is what we’ve heard:

First and foremost, Paterson allegedly wanted a woman for the job. Then, of course, there are rumors that Paterson picked Gillibrand to help his 2010 election bid. From The New York Times:

Ms. Gillibrand’s selection was a careful political calculation by the governor, who will run for his second term as governor in 2010, when Ms. Gillibrand will also be on the ballot. The choice reflects Mr. Paterson’s thinking that his selection should be someone who can help him attract key demographics — in Ms. Gillibrand’s case upstate New Yorkers and women.

As if that’s not enough, the governor reportedly took up Sen. Chuck Schumer’s advice. Schumer, a Democrat from New York, was lobbying Paterson to give the seat to Gillibrand. "He’s had enough competition with a fellow star senator," one Democrat told The Buffalo News, referring to Schumer having to share the stage with Clinton.

Paterson’s alleged self-interest doesn’t end there. Rumor has it the governor may not have liked the prospects of who would take over as attorney general if he chose current Attorney General Andrew Cuomo. Too bad for Paterson, because there’s now word that Cuomo may run against Paterson in 2010.

Although Gillibrand’s getting much praise from upstate and is seen as a rising star in the Democratic Party, there’s already a bit of trouble brewing for the potential senator. She’s known as "Little Hillary" by critics who claim she thought she should get Clinton’s job. Gillibrand’s views are more centrist than liberal, and on some issues, a bit more right than what some liberal downstate Democrats would like. For example, she’s been endorsed by the National Rifle Association, opposed the federal TARP bailout program to rescue banks and isn’t exactly a strong supporter of gay marriage. She also last year voted in support of a Foreign Intelligence Surveillance Bill, which would have given the government authority for warrantless monitoring of communications among foreigners, including communications that pass through this country, such as on Internet servers.

Though Gillibrand’s got the Senate seat, she may have some competition in the coming election. Rep. Carolyn McCarthy, D-NY, said Thursday that if Gillibrand got the job, she would likely run against her in a primary in 2012. Sources told The New York Post that "at least five" members of the state’s Democratic congressional delegation called Paterson to protest Gillibrand’s selection.

But one has to remember the New York City area is in no way a reflection of the rest of the state, which is much more Republican, or, at the very least, typically less liberal than downstate. And another centrist in the Senate may be a nice breath of fresh air.

Click here to read wOw’s "6 Things to Know About Kirsten Gillibrand."