Personally, I think that VIPM would cover most of the needs of code sharing if it wasn't for one HUGE limitation which is a public, free, open repository. The LabVIEW Tools Network repository is great for sharing code that has been vetted and approved by NI's engineers and processes. However there's obviously a huge need for a public repository that has little or no barrier to entry. And even if somebody created a repository like this somewhere (LAVA maybe?) nobody could access the repo unless they pay for a Pro license of VIPM per-user.
Now what Derek/MGI have started with GPM is an awesome first step in solving this, but I think there's one big disadvantage: there is now one additional tool for installing G Code (reminiscent of https://xkcd.com/927/). If I have a project that uses some NI toolkits, some LVTN toolkits and some Open Source GPackage toolkits, I have 3 different tools needed for getting a system set up. I also have three different places (not counting the numerous GitHub repos, LAVACR pages, internal code repos, etc) to go looking for the code I need.
What we need is a single tool that will install everything from all sources in the same standard. I would also want some way to differentiate what's an official NI product, whats a validated LabVIEW Tools Network product, and what is a use-at-your-own-risk open source ...thing... It would also be great if users could rate and review all these things so you could have more information on which of the 7 JSON toolkits is the best for your needs.
I also realize the fallacy of pointing out problems without solutions, but as I'm not in the business of making package management tools, it's hard for me to prescribe others what to do with their time and money. Hopefully this discussion bubbles up to the right people who ARE in this business so we can get the solution the community needs.
[Edit: Darn, in the time that I was typing this, it looks ShaunR posted almost the same ideas, just more succinct... Glad we're on the same page]