Question / Concern #1: Meteor Guide, Alternate Stacks, and MDG’s maintenance of parts of the current Meteor stack.
Yes. We sell commercial support of the current stack to companies that have built their businesses on it. It’s not going away.
We’re going to continue improving support for other view layers (Angular and React) until they’re at parity with Blaze, including the Guide. In the longer term, we expect that most of the usage will gradually shift from Blaze to Angular and React. How long MDG maintains Blaze will depend on how much usage Blaze continues to get in the community, especially among our business customers.
Question #2: Will there be some kind of relational database support directly by MDG soon? I ask this both open ended and specifically regarding the existing stack–reactivity, accounts package, etc.
Absolutely, this is a major priority and we now have multiple people working full time on it. When they have something that’s enough to get early feedback, they’ll share it here. Yes, it has to be full support including the accounts package.
Question #3: How will Atmosphere (also recommended by the Meteor Guide) play along with NPM packages?
Meteor 1.3, which you can try out (and give feedback on) in prerelease today, includes massively improved support for npm as part of the ES2015 modules support.
In the long run, I think we should transition fully to npm. Whatever strengths that the Meteor package system has, we should work with the npm community to bring to npm. This is a big project and is not going to happen overnight. The improved npm support in Meteor 1.3 is a good next step. A later step will be to release the Meteor core packages themselves in npm.