Thanks, exactly what I was searching for. Quoting from "Reconstruction filter" page:

  Practical filters have non-flat frequency or phase
  response in the pass band and incomplete suppression
  of the signal elsewhere. The ideal sinc waveform [..]
  would require infinite delay.

So it's all good in theory, and it depends in practice. Any idea what is the highest frequency "recomended" in a typical audio that will not cause trouble for consumer grade DACs?

That is, if I'm mastering, say, for 44.1kHz, what is the recomended antialiasing filter?