Upgrading to Hoary

[Sean Miller]

Right,

Having now been running on Warty since early December, and having been 
very happy with it, I think it may be time to upgrade to Hoary.

Question is...

a) Are there great dangers in doing this? Could my system completely die 
as a result?
b) Is it a reasonably "seamless" process?

Also...

I have some space on my XP partition...  can I back up Warty to that so 
that I can return to it later should a disaster happen and, if so, which 
filesystems should I back up and which are not so important? Clearly it 
is the system files that will, presumably, be needed to get the system 
back should the unthinkable happen...

Sean