I agree that it's about time, but I think Apple beat them to it on push notifications. Gmail does work with iOS 5 notifications through the default mail app.
Which heaven forbid you try syncing anything other than Mail. Contacts and Calendars have some very subtle bugs which snowball over time (and even on Google Premier Apps).
The biggest one for me is that contact photos resize down to tiny thumbnails after any sync with Google Contacts. There've been a thousand complaints in Google forums for the last two years and it's still unfixed.
Google Contacts also uses a different set of field names, and will frequently sync "main" to "other", for instance. Or just mess up field formatting, or break gtalk ids...
Yep, I can confirm dealing with these issues for years myself as well.
As soon as iCloud was released, I happily ported over my contacts. It's been a much better experience so far (I can finally use large contact photos!).
I thought about doing this. Do you store the canonical versions in iCloud and push them Google or have you just left Google behind? How did you go about setting it up?