I'm going to have to disagree here. falktx, the guy behind KXStudio, has written a very useful script called pulse-jack that configures Pulseaudio automatically to work with Jack. I have found this to work better and require much less configuration than alsa-jack and allows me to use Skype and Google Voice Chat for my podcast. I also use Torben's Flash Jack driver and this setup doesn't interfere with pulseaudio or jack. There is NO way to get the current version of Skype working with Jack without using Pulseaudio. I have spent years perfecting my podcasting setup and thanks to falktx I'm now closer to the perfect setup than I ever have been before. I haven't had any issues with his packages and I use it for audio everyday. I use both KXStudio and his PPAs on top of vanilla Ubuntu and I've never been happier.
The fact is that Pulseaudio is winning the widest adoption and thanks to the pulse-jack script Pulseaudio works very well with jack.
Daniel Worth
Host
The Open Source Musician Podcast
http://opensourcemusician.com