The initial TTA segment, from 9th Street in Durham to Government Center in Raleigh will cover 28 miles with 12 stations. They say that it will open in 2008, but I'd guess mid-2009 is a more realistic projection if they get the traffic projection fiasco sorted out. Extensions to Duke Medical in Durham and Spring Forest Rd in Raleigh will be constructed at a later date (2011?)
There has been a major investment study regarding the corridor from Triangle Metro Center to Chapel Hill, and one of the options was an extension of the DMU-based Regional Rail line. Service to RDU airport is also being considered; direct DMU service is not possible but one option being considered is building an RDU peoplemover and then extending it three miles to Triangle Metro Center.
Raleigh may not be that big of a city (340,000 people, was it?) but the metro area has over a million people, and we have our share of traffic problems as the whole area is quickly turning into a raleigh-cary-morrisville-durham megalopolis of sprawl. The regional buses running between the cities usually end up significantly behind schedule at rush hour because of traffic jams on I-40 and NC54, and the delays are expected to get massively worse as more of the state's highway funds are shifted to the "economically disadvantaged" counties down east. If they build the rail system, I say let the folks down east have the highway money. It doesn't bother me too much that our highways go to hell at rush hour every day. That's what needs to happen for people to second guess our completely auto-dependant development patterns.