Android will still support ActiveSync. Personal Gmail accounts will stop being able to utilize that, but Android itself will be unaffected because Gmail will be native. IOS devices have a Gmail app that is available for download, so the impact there will be minimal. This is just a punk move by Google since they will support ActiveSync for paying customers (Business, Education, Government), and hose everyone else. Bad form.
I have a google account for education so I won't be as effected like a lot of people will be. I recently opened an outlook.com email address and I am looking to migrate personal mail there and keeping my work email on Google.
The only thing that will change Google's mind is if Windows Phone starts taking a larger market share. Rooting for that to happen.