According to Google's "Information for web developers" page (emphasis mine):
Internet users have an increasing number of choices for web browsers today, including Firefox, Safari, Opera, and now Google Chrome. Sometimes web pages look and work differently in each browser, so it's important to test your site across all of them to ensure all your visitors can enjoy the experience you've designed.
Thank you, Google! Now let's see if you can practice what you preach, and get all those services working smoothly in Opera at all times.
It's also nice to see Google acknowledging Opera now, as they have mostly failed to do so in their Chrome PR material. They've borrowed heavily from Opera, but have only mentioned Firefox and Safari.