[aaron42net]

That depends on how you define fair, I guess. If this isn't a hardcoded bonus for "google.com" and instead all established, high-PageRank sites receive the same benefit, is it still not fair?

There's a not well-known component of Google ranking that acts sort of like a slow-moving, domain-wide PageRank. And because they launched domains.google.com as a subdomain of google.com, which contains PageRank 10 pages and is therefore very trusted, the assumption is that domains.google.com is also very trusted, even though it currently seems to have no inbound links from other google.com pages.

This effect is usually hidden because it's rare to have a highly ranked page with no obvious inbound links competing on an established keyword.