It would be nice to have the ability to draw ellipsoids or specify a major/minor axis at each point and glyph an ellipse at each point using those axes.
There is a feature request for an ellipsoid source here:
I have written an ellipsoid source filter and submitted it to VTK.
This should be very easy to add to VTK/Paraview.
Ricardo Reis commented
I think this is the same request has the integrate the hyperstreamline filter to paraview (sort of)