Recently, an interview with Oda-sensei was published in the Yomiuri Shimbun (Newspaper) in Japan. Here are highlights of the interview:
One Piece is “80% done”
At least one more person will join the Straw Hat Crew
Oda initially planned to assemble a crew of 10 people within 1.5 years
Oda’s favorite characters are Ivankov and Bon Clay
Oda adores Buggy while Luffy is his ideal child
Oda is grateful to his female fans, but his main target audience will always be young males. He doesn’t intentionally put any sort of message (inspirational, political, or otherwise) in his manga.