What was the motivation behind forking the distro rather than building packages and an apt repo for Debian or Ubuntu? This is certainly a neat desktop environment, but it always makes me sad to see things done in a manner that makes it difficult to use with other distros.
All of these things have changed since over the past year or so, and there's been a lot of internal discussion about moving to Debian. In fact, it's almost sure to happen for Isis+1 (Isis is the name of our next release).
Basically, setting up our own repo took really good packagers (we have them now, and you can also get pretty much all of our software from Gentoo and Arch), running our own repo required a solid and cost-effective server (we have this now), and forking let us inherit a LOT of stuff we didn't have the resources to customize back then.
As we grow, it seems only natural that we base less on Ubuntu. But a lot of us used to be Ubuntu developers/enthusiasts, and a bunch of us have good ties to the Ubuntu ecosystem (a number of us met up at UDS-O), etc.
I must give you a heads up about moving over to Debian: currently, Debian installers do not have the option to format or install onto a BTRFS partition. (Nor does Fedora's installer, without difficulty. Ubuntu's does though.)
This matters to me because I was recently checking out an interesting installation method that allowed me to do away with Linux partitions by solely using BTRFS subvolumes. (If you look at the IRC chat logs of #btrfs, #archlinux-newbie, and #elementary, I was btrfs-newbie trying it a few days back.)
As of now, I am nearly done with my laptop set up, and I am happily running Arch Linux and elementaryOS with a shared /home subvolume all under the same BTRFS partition. This is a really neat feature that I could take advantage of in the Ubuntu installer (Ubiquity, was it?). I did not have this issue on Arch because Arch's installation method was practically a chroot and create the filesystem and package structure in the proper places.
Please keep this in mind when moving forward. It would be interesting if you can maintain that aspect in your next release, Isis. Thanks so much for your time, and keep up the amazing work!
Feature request - one of the few things I'd hate to give up by leaving Ubuntu is the PPA system, however the one thing I don't like about it is that it puts potentially untrusted (or at least not systematically vetted) PPA packages into the system folders.
An interesting improvement of that would be a PPA system that uses Debian's awesome Update Alternatives tool to install PPA's to, say, /opt, soft link them into the system folders, and then manage side-by-versions, rollbacks, etc. with update-alternatives.
By way of example, the Rbenv in Ubuntu repositories was rewritten to use Update Alternatives to manage Ruby version shims. It would be really interesting to have an entire PPA system similarly based on that.