Reinstall recommendations?

I'm currently running 32-bit Xubuntu 8.10 and I'm thinking of changing over to 64-bit Ubuntu 9.04. Any recommendations on how to make this go more smoothly?

-----Post Update-----

Can I shuffle around the partitions and install it as a second OS? Is there a good way to do that?

Ubuntu asks whether you want to install as a second OS or a new installation, and there is a graphical partition editor within the installer. Surely you will need to make a backup of your data before doing this.

if you have grub installed into the mbr, you can use a joint /boot partition.