One flaw lies with the system itself. Even all characters in the Greek/Roman mythology will not suffice. There's not enough of them to match all the exoplanets--which will probably number up to thousands in the next few decades.
Another thing is that the state of affairs in human politics involved in naming things is out of whack. We can't even agree what a planet is. So i understand why IAU does not want to jump in on it.
So if you'll allow me, I'd like to suggest a fun way to name exoplanets.
Let me start by saying that I have trouble remembering names, and that I love mnemonics. Thus it only leads me to one simple idea and one simple system to go about naming exoplanets.
I think that the host stars should be given more memorable nicknames. Then the names of the exoplanets they hold will follow from that.
For example, instead of HD80606, lets call it "Bogog". Then we'll have "Bogogbee" for its exoplanet.
HD156411 b will then be called "Isgaiibee", HD16141 b will be "Igiaibee". HD190360 b will be "Ipoegobee". And it's sibling will be "Ipoegocee".
If you look closely, you'll notice a very complex multi-dimensional pattern in how I name it. I'll let you figure that out, all you geniuses!
I know that using my system makes the exoplanets sound all weird but hey, it's fun! It makes me laugh just reading those numbers.
Links:
List of Proposed Exoplanet Names
