The RT project includes a number of different runtime related technologies at Eclipse. You can get involved in RT by joining one of the efforts in a current project or proposing a new effort. RT is managed by a PMC that holds open phone meetings on a regular basis. See the meeting calendar for details and the PMC page for more details on the meeting agendas and minutes.
A number of marketing and community activities are being organized through the RT PMC. Details can be found on the RT Marketing.