I use pulseaudio on my OpenSuSE. When the system is installed, I always find
that there is no pulseaudio package in the system. So I have to launch YaST and
install it myself. This seemed very odd to me, until some time ago I decided to
watch the installation logs which YaST shows on the screen, and I saw a message
saying 'removing pulseaudio...', as if removing a package during system
*installation* was an absolutely normal thing to do.

The first thing that YaST does during installation is... removing the
alsa-plugins-pulse package:
http://www.imagebam.com/image/9325c5385921321

...then it does some work 'enabling' pulseaudio:
http://www.imagebam.com/image/9b6486385921323

...and then deletes it:
http://www.imagebam.com/image/7fd768385921325

What's more, on previous version (13.1) YaST asked me whether I want to enable
pulseaudio (there was a checkbox named 'enable pulseaudio', and I always made
sure it's checked):
http://www.imagebam.com/image/660963385914973
http://www.imagebam.com/image/8e3cf7385914976

And yet after system install I still had no pulseaudio package:
http://www.imagebam.com/image/c9dafc385914978

I've installed OpenSuSE 13.1 and 13.2 on about a dozen of different PCs and
laptops with completely different configurations, and the behavior was exactly
the same on all platforms and with all distribution versions.
Please note that I don't do any specific settings modifications during
pre-installation sequence.