Remember that Meteor only just reached v1.0. There still is much to come from the platform. Redis support is being implemented currently, and shows great promise: https://groups.google.com/forum/m/#!topic/meteor-core/Jl5Jt7... Several people are working to integrate standard SQL support, too: https://github.com/numtel/meteor-mysql http://www.lshift.net/blog/2013/02/25/live-updates-to-meteor...

It was a big concern at first for me, too. But the platform is so much fun to develop with I decided to start developing with it anyways. Seeing the pace at which things are developing with the platform, and knowing about these non-Mongo data store efforts, I am certain that this won't be a drawback for the platform for very long.