Yes, its kinda funny, I mean package managers are probably the ones with the most solid experience in dependency management and when I look at them I can see many different concepts at work there. Some like for example pacman are bold and are not afraid to break a system during upgrade (as it is very unlikely that the upgrade will fail) and others put an abnormal amount of effort to ensure an always functional system at any time (especially on source based distributions, e.g. paludis).

And while I have been using development snapshots for years with my system and didn't have more bugs to cope with compared to other systems, I can understand that developers in corporate contexts need to be able to specify dependencies with versions. So I appreciate that proposal very much and hope it will lead to a better solution for every body involved by providing a way to use versioned dependencies without introducing too much overhead for those who don't need versioned dependencies.