MacShrine believes that Apple will update the MacBook Pro to use Core 2 Duo "Merom" processors at Photokina (in addition to the anticipated Aperture 1.2 update). According to the site, Apple will employ the 2.33 and 2.16 GHz variants of the chip, however there is no mention of any other updates (enclosure, etc). The MacBook Pro was last updated in April 2006 with the introduction of the 17" model.
At this time, MacBook updates are not expected despite consistent worldwide shortages, which was anticipated in Apple's most recent financial conference call.
Apple will be hosting a special event on September 25th (just before the beginning of photokina, which begins on the 26th).