skrenta - 8:19 pm on Jan 2, 2011 (gmt 0)
Thanks everyone for their thoughts on this.
I dug into the issue on our side and learned that we had in fact decided to treat meta noarchive as equivalent to meta noindex, but that this had not been turned on in the code.
We've corrected this, so going forward blekko will treat any meta noarchive pages it encounters as meta noindex, and will not index them. This will take a little time before it is pushed to our production servers and makes it into our indices, so please be patient.
Thanks, and happy new year.