They dropped the Microsoft Exchange format for syncing contacts in favor of the open cardDAV format, so that's one piece of data the points in the other direction.

[Edit: originally typed "calendars" instead of "contacts".]

> They dropped the Microsoft Exchange format

For free customers. It's still there for us paying customers. Google pays Microsoft a licensing fee for use of the EAS specs.

Several is "more than two but not many" according to Oxford Dictionary, so three should count as several.

Doesn't whitelisting amount to closing of interface? They may very well use the CalDav protocol which is open, but how good is it if the consumption interface is not open?

Perhaps it was done to prevent spam, or to prevent misbehaving clients from wreaking havoc on its servers.

From hearsay, I understand it's reasonably easy to get on the whitelist if you're a moderately-known app developer or a legit institution. This would lead me to believe Google's reasons are less nefarious in this case.

4) Dropping native RSS support in Chrome

Can't drop something you never had. As far as I can remember, it's always been an extension.