Yes, you can import your characters from Wizardry 6 to Wizardry 7 and from Wizardry 7 to Wizardry 8 (though not from 6 to 8 directly, off course), if you finished the previous game. This even has an effect on the beginning of the game, since you have different options to finish the games.
As far as I know, not everything will be imported, though. Equipment, i.e., will be lost, and some skills may change, since in Wizardry 7 new skills where added to the list. I never finished any of the games, so I never tried it myself
But THIS time, I'll play them to the bitter end...