After some rants about the status of different Qt-based serial port libs, I'm happy to announce that today QExtSerialPort was accepted in Debian experimental (this last link may give a 404 for some time, that's ok).
A great effort was done upstream to put the source in a suitable state for being included in Debian. Thank you all guys!
I packaged a beta version, so I uploaded it to experimental.
In case you are wondering why packaging a lib with (yet) no apps depending on it, the answer is quite simple: there are lots of people already using it in it's home projects (me included). Now those projects have the chance to get into Debian too :-)
As a side note, there is also another nice implementation called QtSerialPort. I have also tested it and works pretty fine too. It aims to become part of Qt as an add-on someday.