I've just started using Ubuntu Edgy (Kubuntu), and I've discovered some nice Debian/Ubuntu/Adept/Amarok integration.
I'm actually at home, and I'm running Kubuntu Edgy on a partition on my parent's machine, but I have my own hard drive with a USB enclosure, so I bind mount my own home directory over my home directory on my parent's machine, so I get all my own settings etc. For day-to-day usage, this is faster and less hassle that chrooting my entire system from my hard disk, but the only thing is that I don't have all my apps installed on my parent's machine.
So today, when I went to play some MP3 files in Amarok, I found it didn't have the MP3 codecs installed. However, Amarok offered to get them installed, and on my say so and password, it modified my apt-get sources.list with the correct edgy repositories, and launched Adept to install the necessary packages. And it all worked very nicely. I found the distribution dependent stuff for this is in a script in /usr/lib/amarok/install-mp3. It's a very nice touch, and implemented in this way it is pretty distribution neutral.
There are some other nice things in Kubuntu Edgy - the 'Print' button launches ksnapshot, making this button work far nicer out of the box than it does in Windows. There aren't a huge number of changes, but these incremental tweaks are always welcome.