upgrading form 7.1-RELEASE to 8.0-RELEASE?

[Tom Worster]

as usual i let things slip until the servers are a couple of versions behind
and then i face the worries of upgrading.

will freebsd-update -r 8.0-RELEASE upgrade work on a 7.1-RELEASE system or
do i need to take intermediate steps?

does anyone have experience or advice they'd be willing to share?

and if all goes well, when i boot 8.0 are my deamons going to start and be
happy:

Server version: 5.0.87 FreeBSD port: mysql-server-5.0.87
Sphinx 0.9.8.1-release (r1533)
Server version: Apache/2.2.13 (FreeBSD)
PHP 5.2.11 with Suhosin-Patch 0.9.7 (cli) (built: Nov 20 2009 16:10:58)