Are There Recent Findings on Earth-Sized Exoplanets and Instrument Limitations?

[madman143]

I was wondering if anyone could indicate me towards recent(and respectable) findings over the number of Earth type planets in the galaxy. examples of exoplanet studies and the like would be great. thanks a lot.
And also findings on the number of exoplanets surrounding stars would be most appreciated.

 

[Chronos]

Earth sized planets are very difficult to detect, largely due to instrument limitations. NASA's Kepler mission is the most recent entry into this field:
http://kepler.nasa.gov/

 

[student1307]

Earth sized planets are very difficult to detect, largely due to instrument limitations. NASA's Kepler mission is the most recent entry into this field:
http://kepler.nasa.gov/

On a similar note, I am looking for a list of planetoids, and I am interested in their masses. I found a comprehensive databases at http://www.cfa.harvard.edu/iau/lists/MPLists.html
(at IAU Minor Planet Center). All these databases, contain orbital parameters, magnitudes etc...but apparently no masses.?? is it because mass cannot be determined from the orbit, so one has to use proxies?