I see this too. And I have stopped watching I/O yearly due to the incessant changes of UI every year, undoing what the recommended the previous year (position of buttons, menus, slide out menus). It is wearying. Nobody would accept that kind of stunt on other platforms, eg. PC.
They are in a difficult situation though - if they don't announce new stuff, the short-sighted industry will think they are stagnating, instead of being robust and reliable and having mature APIs that you can count on not to change.
BTW I must say I am happy with Android as a platform and phone (got a Wileyfox Swift with update ROMs from Cyanogen) but as a developer I find the ping-pong changes tiring. I'm not here just to bash Android.
They are in a difficult situation though - if they don't announce new stuff, the short-sighted industry will think they are stagnating, instead of being robust and reliable and having mature APIs that you can count on not to change.