Hi @MilesMeraki please do keep making wishes and share the use case for the vMX with your Meraki or Meraki Partner reps to check with the product team. To your 2nd question, yes, some things are in the works , keep checking the release notes for the beta versions on the Firmware Management page, and also ask your Meraki team if you can be included in the application analytics beta.
Regarding Viptela, it's still pretty new, but I wouldn't expect any sudden Viptela IP integration into MX, they will each have unique capabilities for different use cases and different customer requirements, granted with a little overlap. I'd expect you'll see continued MX deployments for existing Meraki customers where you need full-stack management with integrated threat management (AMP, IPS, URL Filtering, etc) and all the goodness of Dashboard for simple cross-functional management, reporting, monitoring & troubleshooting. And you'll see Viptela continue to be deployed for existing Viptela or ISR 4K deployments and where you have more complex deployments like per-VRF customization & topologies, WAN acceleration and TCP optimization, and/or need end-to-end secure WAN segmentation across private/public cloud infrastructure. And of course there will be some overlap, both solutions will fully cover your L3 VPN overlays, with transport independence, L3-7 policy management, config templates, 4G/LTE failover, virtual AWS/Azure platforms, etc.