Yep, just tried it. Firefox not supported, Chrome works fine. It's like Microsoft in the early 2000s all over again.

Hehe, I was just thinking of the 90s.. http://www.anybrowser.org/campaign/

This can't be intentional, can it?

Even if it is intentional, they'll still claim it's an unfortunate mistake and just backpedal from it if the pressure is high enough.

Edit: there really isn't a downside for Google. If no-one complains, then they get a clean shot at locking out a competitor. If they people complain loudly enough, they can just revert the change and pretend like it was a mistake. Within a week the whole episode will be forgotten and they can just cook up another scheme.