I'm planning an upgrade from Debian 6 (Squeeze) to 7 (Wheezy), which brings along php 5.4 and omits Suhosin.
Rightly or wrongly, Suhosin gives me a sense of security, because it lets me know about (some) hack attempts. e.g. I notice that my site gets a lot of hackers trying to send really long _GET variables, which are thwarted by Suhosin. I don't know how these long variables are used to hack stuff - perhaps a vulnerability that no longer exists in PHP 5.4?
I keep reading generalities like "oh, don't worry, loads of good bits from Suhosin have been adopted in PHP core now".
Can anyone summarise or point to exactly which of Suhosin's features are included or unnecessary in PHP 5.4?