I like this bit at the end:

"About the data: The June and July results represent the first results published that were collected with a new Nielsen MegaView Search methodology. Because of these changes, this data - and all related search figures from Nielsen - cannot be trended with results that were collected by the company before June 2009."

Nice of them to collect using the old methodology in parallel so that we can compare the results over a couple of months to see how much of this is sampling noise.

1.3% sounds like a lot, (and it is if you are 5% :) ), but at 66% it is a minor blip.

Other such services show yahoo holding steady, google slowly rising and bing slowly dropping (since the launch peak).