Korea just announced its reserves rose by $4.7b in December. Korea's economy is (ballpark) a quarter of China's size, so$4-5b is substantial. It is analogous to $20b or so for China. Korea clearly intervened heavily in December. It is also the first central bank in Asia to report its reserves data. I am quite interested to learn how much China had to spend to maintain its dollar peg in November and December. Judging from the data coming out elsewhere in Asia, the total could be shockingly large. China was spending $20b a month even when the dollar wasn't under pressure.
Russia's reserves, incidentally, reached $299b just before Christmas. They were up $9b in the first three weeks of December. Brazil's reserves are also growing, though not by quite as fast a pace. And so on.