[pc86]

Do you ask because you are rewriting an existing large scale application (if so, why are you rewriting and why are you considering a different stack altogether?), or because you are starting a new application (there is a 95-99% chance it will never need to scale so the question is not terribly important unless it's between this and one similar technology for some reason)?

[dandv]

Exactly. And by the time you do need to scale, Meteor Development Group will have released Galaxy, the enterprise-grade Meteor hosting platform, which is their money maker.