I'm not certain when this will be implemented, but here's a page of the major changes.
Rough explanation: the Missal is the text of the Mass, the part that (unlike the sermon) is the same at Masses all over the world. The official version is in Latin, and it's translated into all the other languages, but the English translation we've had for decades doesn't always match the Latin and is dumbed down in places. This irritates people like yours truly, but now it's being fixed.
Most changes are small. One of the biggest is that in the Confiteor, which is the part at the beginning where everyone confesses his sins, the "mea culpa, mea culpa, mea maxima culpa" is no longer shortened to just one "through my own fault", but is now accurately rendered "through my fault, through my fault, through my most grievous fault," which gives you an opportunity to beat your breast three times just like in the TLM. :)
The fact that it was so obviously mistranslated in the first place, by those who were charged with producing an accurate translation and not a paraphrase, makes me speculate on their possible motives. "This is too hard, it's too embarassing, we can't ask people to dwell on their sins like that..."
So I'm happy to see some evidence of that spirit being eradicated. Of course priests do have the option of skipping that Confiteor entirely and substituting a shorter one, but even the shorter option's been toughened up a bit. Heh heh heh. :)