If people are happy with Jaunty or even Hardy there is no need to upgrade to
Karmic. Any upgrade poses hazards. There could be changes in the kernel,
Xorg, HAL or in Ubuntu itself that causes your system to become unstable. We
saw that last spring when graphics handling capabilities were switched to
the kernel and Intel and ATI users were left out in the cold, while Nvidia
users had no problem. It wasn't Ubuntu's fault, but the manufacturers. Some
users were disgruntled anyway.

An upgrade should be approached with caution. If you do not care about new
features and having the latest and greatest and if stability is your prime
consideration do NOT upgrade. Ignore the hype and be satisfied with the LTS
releases. A new one comes out next April. look forward to it.

If you upgrade then you must be willing to resolve problems. Otherwise
don't. There is no prime directive that you must follow the six month
release cycle. I say this for people still sitting on the fence and unsure
whether to upgrade or not. It all depends on you and your needs.

For most people upgrades go smoothly. If they have gone smoothly in the past
then they likely will again, but there are no guarantees.

Grub2 comes when you do a fresh installation. My upgrade kept my old grub
which is fine by me. I have an experimental partition with 9.10 from a fresh
installation and it installed grub2.