For this year only, the following innovations are so far I remember that I've enjoyed.
- Priority Inbox - one of the smartest way to sort out your email is to use this feature
- Google Voice - Chat within a browser is not new anymore but, a voice call to mobile and land line phones within a browser is really new this year. Although competing with Skype's VOIP is something like rocket science exploration for Google.
- Drag and drop with Gmail - I'm really enjoying this Gmail's feature as it lessen my time looking for the file i wanted to browse. Also, if you're using Chrome, you can also save it by dragging the link onto your desktop to download it.
- Google's Instant Search - One thumbs up! The other one is for missing the accuracy of what we wanted look for.
P.S. Google Wave waves goodbye but it was opened-source to developers for further contribution from open source community.