cvsup newbie questions

[Kevin Smith]

I'm interested in upgrading to gnome 2.8 (and possibly the newer 
releases of other applications)...I'm running the following version of 
freebsd:

 5.3-RELEASE FreeBSD 5.3-RELEASE #0: Fri Nov  5 04:19:18 UTC 2004     
root at harlow.cse.buffalo.edu:/usr/obj/usr/src/sys/GENERIC  i386

In starting to learn cvsup, I'm trying to figure out what I need.   

The "src-all" collection seems like it is more than I want to update.   
Freebsd seems to  be working fine on my system and I don't think that I 
want to upgrade any kernel or OS-related programs unless any 
applications that I would want depend on it.

So, if I am just interested in the latest fixes/version for applications 
running on 5.3-Release, should I just upgrade the ports collection ?  
There is an example supfile in /usr/share/examples/cvsup/ports-supfile. 
Would this be the best configuration to use ?

Also, when I do upgrade the ports tree, I'm assuming it will just 
upgrade the skeleton tree, correct ?  Even if I do upgrade "src-all", 
its not going to down load the .tar files for all the source code ?

Thanks  -K