That is just plain weird, but I have noticed that my fans were turning up in the past few weeks. I suspected Chrome, since it is always going weird. My memory and CPU indicators were up, and I used a temperature utility that said the CPU was 45oC. Now, its down to 42 and the memory bar is way down. Best of all, the fans are quieter.
This is always the wonderful world of Linux. Two steps forward, and one back. :)
Update: After several days, the temperatures are back up again.
Up2: Another general upgrade and it's down again. I must be taking crazy pills!