One of the first things the US Constitution does is setup a national legislature.  In Article I, Section 1, the United States Congress is established, and Section 2 defines it:

The House of Representatives shall be composed of Members chosen every second Year by the People of the several States, and the Electors in each State shall have the Qualifications requisite for Electors of the most numerous Branch of the State Legislature.

No Person shall be a Representative who shall not have attained to the Age of twenty five Years, and been seven Years a Citizen of the United States, and who shall not, when elected, be an Inhabitant of that State in which he shall be chosen.

Following the abolition of slavery, the 14th Amendment further clarified:

Representatives shall be apportioned among the several States according to their respective numbers, counting the whole number of persons in each State, excluding Indians not taxed.

The bold-face has been added to emphasize a simple point:  to qualify for representation in Congress requires statehood, at least so long as the Constitution is followed.  But with the filing of the District of Columbia House Voting Rights Act of 2009, Democrats in Congress are attempting to circumvent the Constitution and add a Representative for the District of Columbia, which is by definition not a state.  To mollify Republicans, the bill also awards a Congressional seat to Utah, a state likely (but not assuredly) to send another Republican to Congress, bringing the total number of Representatives to 437.

I am an advocate for increasing the number of Representatives in the House; the current number of 435 was set in 1911, when the US population was under 100 million.  We are approaching 300 million today.  The British House of Commons has nearly 700 members representing a country approximately 1/5 as large as the US.  Increasing the size of our national legislature would bring our Representatives closer to the people, would dilute power, and would make fundraising less critical.  Increasing the size of the Congress could be done without a Constitutional amendment; however, giving voting representation to non-states requires an amendment to the Constitution.

Do US citizens living in DC deserve representation?  I would agree that so long as residents of the District are taxed that they do.  There are a number of ways this could be arranged; they could vote as a District, or they could be allowed to vote in Maryland or Virginia.  However, any such endeavor requires a Constitutional amendment.  Our governing document is clear about the requirement for statehood, and for representation in Congress.  It is also clear about how it can be amended, as it was to allow DC residents the right to vote for President and receive votes in the Electoral College.  This act should be voted down, and if passed it should be struck down by the Supreme Court.