Narasinha: You are saying that the Accissibilty search isn't using different data centers?

I do ralize it is still something in the works.
This would make a bit more since.

1. Site gets marked as accessible or not when a regular crawl is done.
2. The pre-evaluation for accessibility keeps results from being slow.
3. Each datacenter can work off of the already evaluated list of sites to know which should be there.
4. You get your results

It seems silly to have just one place to get these results. That would also mean that the accessible search is only working with english results also?