Yes it's a "rolling" implementation. Here is the link to their FAQ page, look down to compliance.
http://www.tsa.gov/what_we_do/layers...ired_twic_date
New England comes on this week and around the country until about April 2009. It's federal so there may be delays.
I have to go through Portland, OR to get mine, same as I did for HazMat. If you have a background check for hazmat after 2005 you can save $50, but it expires the same time as your endorsement, otherwise it's good for 5 years.
My company is paying $250 to anyone who gets the TWIC, sort of like free money, except for the hassle to get it.