Meteor 1.4 has finally landed and it contains some exciting new enhancements and improvements including updates to Node and Mongo. Make sure to check out the changelog on the github repo for a more descriptive look at what's included.
Okay, so you read the first link in this issue of Meteor Weekly. Now it's time to take a look at this one! Here is your guide for upgrading to 1.4. There are some breaking changes, so I recommend giving this a read.