I found this on Real GM.  According to the Globe and Mail, Bynum already expects to play against Yao and sees Yao as his opponent.

http://basketball.realgm.com/src_wiretap_archives/58869/20090429/bynum_fully_expecting_to_face_yao_houston/#

He already notes that the Rockets have the lead and doubts the Blazers will pull one in Houston.  Gasol also said that the Rockets "probably they will" be able to win the next game against the Blazers.

It seems the Lakers are confident (or cocky) with their words.

Or maybe they're just afraid of Portland?