To put it simply, I loved it. It takes a VERY talented writer to have a season finale which not only neatly ties up all the previous issues, but also, leaves the plot wide opened in the event of another season. Julian Fellowes has that gift in spades. The whole plot of 'Downton Abbey' is almost always seamless and, therefore, it's a pleasure to watch. The cricket match ending is a perfect example of exactly the right spot and I am very impressed.
The unanswered, yet partly answered questions concerning Mary and Matthew, Tom and the baby, Thomas's future, whether Ethel will see Charlie again, etc. were all left open-ended.
I won't say too much more as our American audience is yet to see the third season, but I WILL say that you will not be in the slightest disappointed when you do watch it. Another season, please, Julian Fellowes!!