Ikey, who was the creator of LMDE (although he left a while ago), is now making a new distro called SolusOS. This distro has a lot of interesting features and a lot of interesting ideas for features (they still haven't done a final release - they're on RC2 and RC3 and a 64 bit version are coming out soon). Some of these features could be used in linux mint.
1. SolusOS has a "first run wizard" which in some ways is like the mint welcome screen, but it has five steps which go through whatever the installation didn't cover, like installing drivers. Mint could have a first run wizard like this that asks about drivers, (for people who have the CD version) about upgrading to the dvd edition and adding codecs, and possibly other things.
2. It is based on Debian stable and therefore is very stable, but Ikey himself backports software to it so they have firefox and thunderbird 10.0.2, Libre Office 5, VLC 2.0, etc. Recently, non LTS (for both Ubuntu and Mint) releases have been sort of less-stable - 11.04 brought unity and 11 was a tiny bit buggy because 11.04 was buggy, and 11.10 was less buggy, although unity still wasn't great, and 12 was buggy because of gnome 3. Mint could do a similar thing to the LTS releases that Ikey is doing to debian stable. It could even make an LMDE based on Debian stable which does this.
3. While they are expanding, SolusOS has one version right now (32 bit SolusOS based on Gnome 2.30 and Debian Stable). 64 bit is coming, and so is LXDE. However, they aren't doing this yet. They are only working on the main version. And this is 3 editions in total. Think of all of the editions that mint has. We have 4 LMDE editions (counting 32 bit and 64 bit seperately). The Ubuntu based versions are trickier because many versions skip releases now and then. The last time we had all of the releases done was Mint 9 - we had Gnome 32/64 bit, KDE 32/64 bit, XFCE 32/64 bit, LXDE 32 bit, and Fluxbox 32 bit. If you don't include the Ubuntu based XFCE, you get 10 releases. Also, there are update packs for LMDE and Cinnamon. Frankly, this is too much. Update pack 4 has taken six months and counting to get out. The KDE and LXDE versions of Mint 12 were release about 2 months after the main release. Fluxbox hasn't had a release since mint 9. KDE missed mint 11. I think that the mint team needs to downsize. There are many opinions on how, and I think that we'll have to see what the community says.
4. While it hasn't been implemented yet, Ikey has come up with a way to upgrade from one release to another. Basically, he feels (I don't know if this is true), that upgrade managers (besides the mint one) basically just run sudo apt-get update and sudo apt-get dist-upgrade. When going from one release to the next, they do much the same thing. They rely on post installation scripts to make everything work. If a script was written to guide the installation and to install the packages in the correct way (I know that's vague, but again this doesn't exist yet as far as I know so I don't have all the details. I'm not an expert on the subject, I got this from what he said in his interview on mintcast. This idea is more something to keep an eye on.
5. I think that, in general, we should look at new distros and see what they're coming up with. While linux mint does a lot of innovating, Mint 12 and (I think) Mint 13 were/will be more about the desktop environment, so we should, once that gets smoothed out, get back to adding new features.