I’ve just come across something crazy in 2.8 and I’m really hoping it is a new feature and not a bug because it will be awesome – I accidentally switched to edit mode when I had two different objects selected in object mode, and was able to edit them both! This would be an amazing feature especially when aligning geometry up with other objects that are supposed to fit tightly together. The screenshots below show what I’m talking about :
Two seperate objects selected , one highlighted yellow and one orange :

Enter edit mode and both are editable :
