Conclusions
 There is a relatively wide variety of line profile morphologies seen in Chandra and XMM observations of OB stars
 By combining line profile analysis with other diagnostics, it is becoming clear that a surprising variety of high-energy physical processes are occurring in early-type stars
 Constellation-X:
High(er)-resolution line profile analysis of short-wavelength lines
Ionization structure of Fe complex
Much better S/N and time coverage (X-ray line profile variability?)
Vast increases in the number of stars studied (is there a strong Malmquist bias in the current data?)