Just reading trough the posts…I saw lots of concern about SEO…but actually this is not the case…you can just simply tell google about your app with meta tags and the fragment attribute and now when a robot visits your site… meteor recognizes it and you can prerender the html on the server side which can be now perfectly crowled…
I am just planing to put into production my first meteor app and I must say I am kind of impressed…how easy and quick the development is and how many packages are already out there to help you…of course and don’t really see it fit for long term projects just yet…but it isn’t impossible 
It is like when someone says that what 10 .net developers can do in 6 months…can 2 php developers do in 1 months…you can just simply add to it can 1 meteor developer do in 2 weeks