I agree with "keep it simple" and predict the following:
We know at a glance that $23k means $23,000.00, not $23.00. So going the other way, 0.000023BTC will become known as $23μ (where "$" is substituted for whatever symbol ends up in common usage for BTC). All this crazy decimal stuff might seem hard now because most people are not used to dealing with the mysterious world on the right hand side of the point -- I know I had to count the zeroes and then double-check -- embarrassing! It will become easy though, as it comes into common usage and people get a "feel" for how much $1μ is worth. People who grow up with bitcoin will have NO problem with this.
"You paid 23 grand for that gold plated hovercraft?! Hah, damn, all about the bling with you isn't it? You could've got one with twin reactors for less than 18μ! LOL!"
Yes: bitcoins will be worth that much, and people will still use "LOL" in the future. When we all have hovercrafts.