How do I match the same points (WGS84) in two different point layers? I want to get the points that lie exactly upon each other in the two datasets.
In QGIS 1.7 you can use the Geoprocessing Tools > Intersect
Then if you want the attribution matched you can do a spatial join (join attributes with spatial location in the Data Management Tools) standard tools with QGIS.
The question is not very clear, in any case, when you have layers in different CRS just enable "on the fly CRS transformation" in the project properties.
Please be sure that your layers are read with their correct CRS, looking in the layer "properties" dialog, "general" tab.