I installed Snow Leopard and everything went okay. As usual the first thing that I do on an OS is to check the perl version:
$ perl -v
This is perl, v5.10.0 built for darwin-thread-multi-2level
A few things that didn't work straight away were Apache (dav_svn_module was the culprit, probably the wrong version), make (I needed to install the developer tools separately) and Adblock in Safari (only works in the 32 version).
Apart from that everything looks good.