The announcement by Amazon today of their Elastic MapReduce service is, I believe, a huge step forward in the world of Clouds. This gives us mere mortals the ability to tap into the Hadoop technology (one of the key engines behind Google's power) to cost-effectively process vast amounts of data.
There's some good coverage of it on CloudAve here.
You should also read this post on the AWS blog for more detailed information.
ZeroTouch IT Ltd