Hi Denis,
there was no decision on OsmoDevCon, apart from some opinions.
I'm not aware of anyone actually having reviewed/evaluated rockbox at this point.
The general point was that we apparently don't really _need_ a "full OS" like NuttX, but there are other solutions like rockbox that may bring in other useful parts like a UI for low-resolution dot-matrix displays.
I guess until somebody actually tries and experiments with an early port of rockbox to the calypso, we won't know what is the best way to move forward :/
And in general, everybody seems to be busy with lots of other things, so I'm not sure if (and when) that might happen.
Regards, Harald