Can I update my openSuSE 11.1 to 11.4 directly using an openSuSE 11.4 DVD? or will I need to upgrade to 11.2 and 11.3 first too?
Technically, you're told not to try and skip version like that. It could work, but there's no way of knowing until you actually try it. This happens when you have third-party apps and proprietary drivers and stuff like that.
My opinion is to just upgrade the steps in between and save yourself a possible headache. You could mirror your /home directory in another partition as to not lose any of your data.
Short answer: at your own risk. I would go step by step.