CityCenter DC development schematic model courtesy Hines|Archstone Hot news from the Washington Business Journal this morning on the long-stalled CityCenter DC project. Tierney Plumb reports that mega-law firm Skadden has signed a letter of intent to lease 350,000 sq. ft. of office space at the yet-to-be constructed project planned for the old convention center site. The lease is a key development in getting the long-stalled project off the ground. CityCenter was originally scheduled to…