If the dashboard update was "known" to brick any consoles that have not been previously updated, then it will brick as many consoles as you allow it. The retailer I went to advised me to wait until the issue was resolved. If you do not believe me, call microsoft and ask them.
It probably is just not getting well ventilation..but what about the other consoles..why are they working fine? RRoD is horrible. This on the other hand is not good for MS. They really need to fix that if they stand to win this war. They went from this being a small launch issue to now everyone has either had it happend to them or know someone personally.