Initial 2010 Census results have been released for 5 out of the 50 states, including both Maryland and Virginia. Some highlights from the data:

In Virginia:

• The big news is that Northern Virginia grew enough to affect legislative redistricting. Northern Virginia will soon have considerably more political clout, while the rest of Virginia (especially rural southwest) will see their clout decline. WTOP thinks the shift may tip the overall balance and, for the first time, give urban/suburban areas more overall political power than rural ones. Rural Virginia, as one might imagine, is freaking out.
• The basic trends we’re all familiar with continued. Outer suburbs grew the fastest, with established cities and suburbs growing more slowly but healthily. Compared to the 2000 Census several jurisdictions in Northern Virginia passed important thresholds. Fairfax County topped 1,000,000, Prince William County passed 400,000, Loudoun passed 300,000, and Arlington passed 200,000.

For Maryland:
I looked at Maryland in a little more detail. For one, there’s no big picture redistricting story to dominate, because Maryland is already an urban-controlled state. Also, since most of the population centers are close to Washington, the detailed information is more pertinent.

• The big story is probably that Montgomery County is now minority-majority, meaning whites are less than half the total population. No single demographic group in the county forms a majority on its own.
• Montgomery County remains Maryland’s largest jurisdiction, but still hasn’t crossed that magical 1,000,000 person mark. At 972k, it is getting close. Prince George’s County probably won’t catch Montgomery, but at 863k it added to its lead over third place Baltimore County (801k). Baltimore city is 4th (621k), followed by Anne Arundel (538k).
• With a population of 99,615, Columbia is on the cusp of becoming only the second community in Maryland history to cross the 100,000 population threshold (the first is obviously Baltimore).
• After Baltimore (620k) and Columbia (99.6k), the next largest communities are Germantown (86k), Silver Spring (71k), and Waldorf (68k). However, all of them except Baltimore are “Census Designated Places”, which means they aren’t real cities, but merely convenient statistical groupings.
• The largest incorporated cities after Baltimore are Frederick (65k), Rockville (61k), Gaithersburg (60k), and Bowie (55k). After Bowie there’s a big drop-off to the 6th place city, Hagerstown (40k). It’s important to note that incorporated cities and CDPs really can’t be compared on an apples-to-apples basis, because CDPs are defined more liberally, meaning the populations of incorporated places are undercounted relative to CDPs. Nobody exactly knows what a Frederick or Rockville CDP would look like, but if such things existed they would definitely be larger than 65,000.
• The densest communities with a population over 50,000 are 1) Silver Spring, 2) Baltimore, 3) Gaithersburg, 4) Germantown, and 5) Dundalk. If you drop the criteria to 10,000 population, then it’s 1) Langley Park, 2) Chillum, 3) East Riverdale, 4) Silver Spring, 5) Takoma Park. Savvy observers might notice that the Purple line hits all 5 of those latter communities, and that either the Purple line, the proposed Baltimore Red line, or the Corridor Cities Transitway hit 4 of the 5 in the first list.