Indeed, the PS3 is about five weeks away from launch in Japan and six weeks away in the United States, so the presumed overheating problems may not bode well for final retail units. However, a Sony spokeswoman told the Associated Press that Sony's kiosk at the Tokyo Game Show housed 200 PS3s "clustered together in close proximity," and that overheating problems encountered in such conditions will not apply to home users.
Update: Sony Computer Entertainment International has responded to the allegations by calling the analyst's report "unsubstantiated" and saying it was not aware of any incidents at the Tokyo Game Show where PS3 consoles needed to be rebooted. Sony did however reiterate that the show floor conditions were extraordinary and that "if indeed, there was the occasional unit that needed rebooting," it was not due to general problems with the PS3.
Meanwhile, Sony Europe told GamesIndustry.biz, "SCE can categorically deny that there's any problems with PS3 units overheating."