The Senate passed a bill that gives the District of Columbia (Washington DC) a vote in the House. The vote was 61-27 mostly along party lines with two Democrats voting no and six Republicans voting yes.(http://senate.gov/legislative/LIS/roll_call_lists/roll_call_vote_cfm.cfm?congress=111&session=1&vote=00073).
Beyond the blatant political move of giving the strongly Democratic DC a voting member in the House, the bill is blatantly Unconstitutional. The Constitution says that House representatives shall be picked by "people of the several states"; DC is not a state. The bill adds two seats, one to DC and the other based on the population of the states. For the next two years that would be Utah. After the census in 2010 that seat could be transferred away based on the count. Utah was/is largely expected to pick up a seat in 2010 without this bill.
Given the politics, the House will almost certainly pass it and Obama has already promised to sign it into law. It would then likely be up to on of the states to bring a Constitutional challenge against the bill arguing that it diluted their voting power. I can not think of a good legal argument that could be used nor have I come across one meaning the Supreme Court would probobly strike it down.
If they want to give DC a vote legally, they need to either amend the Constitution or make DC a State. They could also merge DC in to one of its surrounding states for purpose of voting for representation.
More at http://www.washingtonpost.com/wp-dyn/content/article/2009/02/26/AR2009022601678.html?hpid%3Dtopnews&sub=AR.