Add Sacramento's California International Marathon to the list of races which are selling out faster and faster every year. The Sacramento Running Association, which puts on the race, told members on Friday that CIM is 88 percent full on Thursday. Last year, the 8,000-runner race sold out on October 15. It appears likely to sell out by September this year. It'll be run on December 2, 2012.
CIM is considered a good PR bet and it's a popular Boston qualifier due to its calendar placement, predictable weather (cool, dry) and net downhill profile. The other major Northern California marathon that is selling out crazy fast these days is the Big Sur Marathon. The 2012 race sold out in 29 days. The 2013 race sold out in 26 hours. (I'm still bitter.)
CIM doesn't include a half as an option, but does have a relay component. The 2012 race is the 30th anniversary, which may be boosting its popularity.