Google Drive's official blog announces features and promotions for Drive, Docs, Sheets, Photos, and storage plans.
HN links it as the official source for announcements such as Photos in Drive, Keep, and free storage promotions.
Google Photos is a very recent addition to Google Drive[1]. I'm not sure the change even rolled out to everyone yet and still not all my photos have been migrated. They used to be only availble through the bizarre web interface within Google+ that OP described.
Despite that, I quite like Google's apps (and Google Apps). The month view in Calendar is back. The upgrade to Lollipop went smoothly for me and was a significant improvement. Some of them seem effectively abandoned (Blogger) but ones that aren't (Drive) are top notch: fast, attractive, full-featured, and with excellent integration between web and mobile.
[1] http://googledrive.blogspot.com/2015/03/photosindrive.html
I heartily recommend everyone with a Google account follow that link and double-check your security and allowed app settings. (Also take some time to go through your app-specific passwords and revoke any that aren't relevant anymore.)
In addition to being good practice in and of itself, Google is currently doing a promotion where they'll increase your Google Drive space by 2 GB if you go through their security checklist (see link below):
http://googledrive.blogspot.com/2015/02/safer-internet-day-2015.html
The official announcement: http://googledrive.blogspot.com/#!/2013/03/google-keepsave-whats-on-your-mind.html
Last sentence: "You can access, edit and create new notes on the web at http://drive.google.com/keep and in the coming weeks you'll be able to do the same directly from Google Drive."
Scratch the "ish". They also released the android app https://play.google.com/store/apps/details?id=com.google.android.keep
Update: Here is the announcement: http://googledrive.blogspot.com/2013/03/google-keepsave-whats-on-your-mind.html
Photos has Drive integration [0] since a couple of months ago so you're free to do exactly this.
[0] http://googledrive.blogspot.com/2015/03/photosindrive.html
2GB free Google Drive Promo: http://googledrive.blogspot.co.uk/2015/02/safer-internet-day-2015.html