For the first time, I have seen Google comment on when they will be bringing push Gmail to any device. In a Google Mobile Help thread, Googler Ethan responded to a request about push and the iPhone, adding that it is supported on Android devices and in July, it is coming to Blackberry devices.
The only catch is that push will only be supported for Google Apps Premier Edition and Education Edition users. That means, you have to pay for it. I personally think that is fair and I know many people willing to pay a few bucks for giving them push Gmail. Again, this is only for Blackberry devices and it is coming next month, in July 2009.
Let me quote Ethan:
As a reminder, push email support is currently available with the Gmail app on Android devices and will be available for Google Apps Premier Edition and Education Edition users with BlackBerry devices in July.
So what about the iPhone? Well, no comment from Google on that yet. It is currently the 7th most wanted feature in the feature request list. But Google has yet to comment about if or when it will be available. I suspect that when it does become available, it will be only available to the Google Apps Premier Edition and Education Edition users, similar to how it is launching for Blackberry devices.
Forum discussion at Google Mobile Help.