I believe there are a number of factors that bring attention to Sphere:

* next generation blog search engine – it has the timing to learn from what has been done before. This, as you point out, doesn’t mean that it is doing thing better or right.
* people – there are a number of people involved in the project that have had experience in blogging for a while.

I agree with your basic point – that Sphere has yet to show any features or qualities that really leapfrog what is currently available.