Wow, such strong feelings on the matter.
To me mBTC makes much more sense, I was all for it when price passed $0.50/mBTC OR $500/BTC... whichever you prefer

we can use them interchangeably easily enough.
I just think it removes a psychological barrier for folk still getting into bitcoin who think the price is 'too high' because they don't necessarily understand the divisibility aspect.
As for what to verbally call them... then I don't know, milibits? I'll leave that to the crowd!