Yes and if you go to Google trends:
http://www.google.ca/trends/explore#q=bitcoin%2C%20buy%20bitcoin%2C%20bitcoin%20mining&cmpt=q
you will get just the opposite, I am a keyword freak, so I notice such things instantly too;-)
Oh, and Adwords tool give you this:
bitcoin
Low
823,000
buy bitcoin
Low
33,100
bitcoin mining
Low
90,500
Competition still shows as low, but not for long. I am trading tags in tagvillage, and there are not many more expensive keywords now that the bitcoin's ones, the main 'bitcoin' costs now 2296.223 CR, 1 tagvillage credit equals 1 US $, so the tag bitcoin is for sale there for $2296.223.
You can enter the tag here and look:
http://www.tagvillage.com/what-is-tagtrading/ and enter some others to compare.