I fail to see why it matters

They just had a long discussion about this on Hacker News, http://bit.ly/SccAvx - Basically this is nothing new and has always been part of the terms. Concerning this particular clause, this quote sums it up:

"The SDK sources are still Apache2, and you can build your own SDK with them if you wanted.
You just can't take the Google-built SDK binaries (except as allowed by a third party license, such as Apache 2), or non-open source pieces, and use them to do it."