So, I was happy to see that my Drupal 6 site survived being moved to PHP 5.4. (I had always meant to do that, but it never rose to the top of my list.) And, when the server moved to a 64-bit machine, it wouldn't run because the php-update.sh stuff described here:
The problem was that the php.cgi it created was still a 32-bit binary.
However, this morning I was looking at the status page on my website and I discovered that the site was still running on php 5.2. I checked the Dream host email again, and my site had indeed been migrated. I looked at the control panel for the domain, and it too thought that the php version was 5.4. And then I thought, "Ahhh, I bet it is the php-update stuff again," and so it was. It took quite a bit to tinkering to get the scripts switched over to using php54.
I don't recall the Wiki page describing the things to watch out for as part of the PHP 5.4 migration even mentioning php-update, but then again no mention was made of it during the migration of the 64-bit machine.
So, my guess is that there are a lot of web masters who think that the migration went well, and whose websites are going to go down when the php 5.2 support is dropped in November.
It would be great if the Advanced_PHP_configuration were updated for 5.3 and 5.4!