To clarify things, I have no ideas about 48 days - the 'testing' banner was published last weekend. Christmas event is a separate thing. You can check in the game news that it *was* published in December. And, as Sjava already said, events are released browser only for a number of reasons.
Also, for your information, the whole developer team is 1 developer and 1 tester. So making updates takes more than a few weeks usually. Thanks for your patience and understanding.