As an addendum, it appears that that ability to assign tasks and set times via email also doesn't work any longer.
That is, for example, if I email email@example.com with the subject "Top Secret Mission @rb tomorrow 10AM" it would previously create and assign the task to my colleague with the initials RB for 10AM the next day. Not so anymore. Will that make a return, I hope?
I'd really like to know about this as well. Any update? We really liked the ability to add notes to tasks by replying via email and using those "Cool Tips" that Stephen pointed out. Would be a shame to not have that functionality any longer...