Looks like the latest patch has followed the MMOG standard of "Fix one problem, break another". Last night's patch has made a little big of a problem - Namely, cities in the Coast of Tranquility area have gone missing, leaving a lot of city spots free.
If the city hunt is still up, do not assume at the city spots in CoT are free. The way that this is being handled is that any cities built in those spots after the patch will be removed and the original cities will be reinstated ASAP.
Just another friendly warning from the invisible AO dude.