Due to quite a lot of feedback in the past 24 hours I've decided to postpone the PHP 5 upgrades until January. It appears that in spite of the 5 months window to work on compatibility issues many people are not ready and the last thing we want to do is disrupt ecommerce sites over the holiday period.
So we'll aim to do this in the last week of January which gives people some time after the holiday to work on upgrading scripts. What we'll also do is leave one or two servers with PHP 4 for a few more months and move anyone there that can't make the end of January deadline.
Dedicated server clients are not included in these PHP 5 notices. If you have a managed dedicated server with us you can request a PHP 5 upgrade at any time.