There has been some recent developments concerning the fate of the Space Interferometry Mission, SIM. They are summed up in the following article on Space Review, authored by me.
http://www.thespacereview.com/article/1711/1/
As you can see in the Comments section, NASA is now in the process of shutting down SIM. This does not bode well for those who seek to study nearby Earth analogs.
Phil H.