Yes, this is a shame and shows clearly that this device was rushed to the markets to hit the xmas business and the good faith of the buyers was abused
by nokia which as was stated by the fortunate testers of the new firmware has indeed a fix for this bug but rather then "release often" and let us use our devices in the end prefers to keep it secret for the next weeks (months?).
This is not the linux way of doing things and I regret to having tought that a non linux shop like nokia would adhere to the linux etiquette of not letting the users hang. By looking at the wl12xx wifi driver code full of todos and fixmes and by looking at the load of patches queued up for inclusion for the next kernel releases which add a lot of missing features I've got the impression that the wifi subsytem was glued together in a hurry hoping for the best and so know we own an unreliable phone that eats a battery in less than one hour if we accidentally forget to reboot it after a two minutes wifi session.
Maybe the spontaneous reboots bug is instead a feature introduced by nokia to stop the battery drain?
I will wait for the new firmware in the hope that it will be release soon, just to give the nokia people a chance to get it done right. My feeling right now is to get rid of the N900 and sell it on Ebay before more people understands that it is utter crap and prices fall.