In Natty, I really enjoyed the "Blue Highlight" feature as detailed in this great askubuntu question: When do things in the new Unity Panel turn blue?
In Oneiric I notice that the upper left corner is no longer the default launch point for the launcher. Also with the absence of the BFB there is no obvious way of alerting to application notices.
I haven't noticed any "Blue" notices in Oneiric beta. I assumed the Session-Indicator would turn blue when updates are available because there is now an update link in the menu. But no joy. And the volume indicator does not turn blue when its muted and music is playing.
Is this because it's beta? I'm hoping the "blue" feature hasn't been dropped. It was great!
For the most part the "blue" feature is still very much present, it has just moved. Individual launcher icons will have blue arrows when they are requesting attention, and the messaging menu turns blue when it needs to alert you to something. I believe the volume icon does the same thing, but I have no tested this, and I usually don't have my sound muted, so I'm not 100% sure.
There is an indicator for updates that AFAIK will be included in the default install.