Peter just pointed me to an article adding to the speculation about Google becoming a registrar: Jim Boykin’s Internet Marketing Blog » Blog Archive » What does Google know about your domain names? by Nick Wilsdon

Nick points out that Google does gain additional privileges by becoming a registrar, such as carry(ing) out high volume automated queries.

It would allow them to track the age of domain names and connect likely networks and portfolios. They would see when a domain name changed ownership and allow them to adjust the value of that domain in their engine.

While their accreditation status would probably giving higher query limits for the registry whois, this whois only contains limited information. For the biggest gTLDs, COM/NET, the whois only contains:

• the domain name
• the creation date
• the expiry/ date
• the last updated date
• the nameservers
• the sponsoring registrar
• the sponsoring registrar’s whois server

The most valuable pieces of information for Google would be the nameservers, the creation and expiry date. In the past there has been some speculation (based on a patent google filed) that they give higher evaluations based on the length of the registration term. I personally do not thing that this is such a great idea, considering that a lot of hobby websites are only registered and renewed year by year. Plus it looks like some names are now actually being sold to new owners without being re-gistered, so they are actually never dropped.

The registry API (at least for the gTLDs) will not give Google access to any additional information - as long as the domains are not registered through them.

I’d like to clarify something: In order to track actual owner information for domains (at least for COM/NET), they also have to query the whois-servers of the registrars, who in turn have their own rate limiting. Don’t get me wrong, it is a common request between registrars to increase the whois query limit, but in most cases this request is only granted in order to facilitate transfers from one registrar to another (for transfers you need a confirmation from the current admin contact listed on the domain). Since Google is not actively selling domain registrations, I am not quite sure how many registrars would increase their whois query limit for Google.
Also it is important to note that getting accredited for ccTLDs is a different process from being accredited for gTLDs, mainly because most countries create their own rules and API systems/access methods.
As Peter also reminded me, registrars also have access to the list of names that will be dropped for the registry, which would indicate a change of ownership.