What would be the canonical way to handle a file upload with Meteor?
There is a new package: edgee:slingshot. It does not upload the files to your meteor server, but it is better that way as it allows the meteor server to focus on its primary objective of serving the meteor app instead of handling costly file transfers.
Instead it uploads files to cloud storage services. Currently it supports AWS S3 and Google Cloud Files, but it will also support Rackspace Cloud Files and perhaps Cloudinary in the future.
Your meteor server merely acts as as a coordinator.
It is also a very versatile and light-weight package.