When I set up my current Debian desktop system ( currently squeeze ) in 2007 I allocated only 8.4G to my / partition. Now I find it is getting too crowded with only about 580M free space (worked around CD & DVD burning by creating a /tmp folder in my /home/username folder). My current plan for fixing this is to use gparted running from a live-cd. I will first delete my swap partition and my /home partition then use gparted to enlarge my / partition to 20G. Next I will recreate & format my swap and /home partitions and restore the contents of my /home partition from backup. I will still have lots of room to spare in my /home partition. My system has no extended partitions. My hd is 250G total.
I know this will change the UUIDs of the two new partitions but am not sure if it
will change the UUID of the expanded / partition. I expect it will. My next step
will be to edit my /etc/fstab and put in the new UUIDs which I will get by running
blkid /dev/sdb. My backup drive is an ide drive, /dev/sda.
My question is am I likely to run into boot problems with grub2? Should I chroot
into my / partition and run update-grub before I reboot or wait to see if it will
reboot first?

How about cleaning apt's cache first and free some space?
8.5GB is almost the sum of the / on 5-6 debian installations I have made for me and friends (/home in seperate partition as always)!

While backing up is a good idea there is no need to delete your /home partition. Just resize the bugger.

The draw back to this is that the resize does take a good chunk of time.

I know it is popular to have cramped / partitions but I like the suckers to in the 20 to 35Gb range. I have a lot of stuff added (apps, themes, etc) and it adds up. I also cull my cache every now and then but like to have it there with everything handy for use in other installs or just reference. I think the buggers run faster if they have enough room to breath too.

Or a data partition with all your personal stuff, and nothing in your home folder except a bunch of symbolic links to the data partition.
Either way, getting all your data out of the root partition is a good idea.