I quite fancy PulseAudio, it's nowhere near jack thou, as the delay is awful. Perhaps i have just got it misconfigured (pretty much standard setup), but it's a system which works for me to route ALL sound applications through it.
I had some hard time trying to get my sound to work simultaenously with multiple applications, but pulse solved that (Only exception is a recent build of w(h)ine which bitches about not being able to open neither the oss padded one, esd, or alsa. And quakewars). But ofcourse it came with a price: roughly 1 second delay when it is filling/emptying it's buffers. [Video/visual is not affected thou.. for some reason it still goes in sync with it.]
Also, it doesn't seem to do good under my realtime kernel, it hangs/freezes/crashes every now and then, even thou it's supposed to be able to run in some kind of realtime mode.
Odd is also that the SDL standard driver for pulse gives loads of static sound and what sounds like xruns. So can't say it's that much supported by it's official sound driver/w/e to call it. It's better at emulating esd sound.

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//Cincerly SteelSide
//Mvh Daniel