Nothing official has been announced but the primary role will be to fill in the gaps from the neighbor islands to the west coast. A few routes that currently see 330s today will become 321s in an effort to add frequency/capacity. It's already been said that there will not be a massive drawdown of 330 flying from the west coast. As for the 767s it remains to be seen if they'll see 1 for 1 replacement by the 321.
The 321 will not be able to handle the cargo volume that is carried on both widebodies. So... where HA carries lots of cargo, you will likely still see the 330. This includes LAX, SFO, OAK, SEA.
For current 767 flying, I wouldn't be surprised if SMF and SJC see the 321. PHX is a bit of a wild card to me. I think it will go 330 from HNL and if possible 321 from OGG. It could end up being a 321 station if it can perform well. The 330 will go to CTS for obvious reasons. This leaves PPG which is an interesting case. Loads are healthy, lots of cargo is carried and the HA service is a lifeline to the folks in American Samoa. HA has always been shy to take the 330 down there, due I would imagine in large part to logistics and fear of taking the "new toy" down there to get beat up by the airport and birds down there. I can't see the 321 replacing the 767 completely for PPG though. Perhaps there will still be the need for maybe 1 weekly widebody and an increase in frequency with the 321. I do however, see PPT migrating to the 321 eventually with an increase in frequency.
Stay tuned... first delivery is next summer!