Upgrading to Snow Leopard was pretty smooth save for a few items.

Sphinx was giving a little trouble connecting to mysql.

Instead of using 9.8.1, we found Sphinx 9.9-rc2 to work better.

Adding this to the config call will install the 64 bit bindings:

LDFLAGS="-arch x86_64" ./configure --prefix=/usr/local --with-mysql=/usr/local/mysql

That should take care of the mysql connection error.