I ran into this fascinating article on Asterisk. It’s a very interesting topic and very important for web designers and web users in general. By D. Keith Robinson These are few points taken from the article.
A few ways you can help your users with a redesign:
1- Make sure you really need a redesign first. There are many, many times when it might not be worth the risk, let alone the time and effort.
2- Set concrete, realistic goals for your new design and stick to them. Don’t get too crazy.
3- Let your visitors know it’s coming beforehand.
4- User test your new design before you launch. At least have a few “user representatives” go through the site and offer feedback.
5- Consider a staged approach instead. Maybe you just need to enhance portions of your site, not the whole thing.
6- Consider a beta version to let people try it out first.
7- Gather feedback about what your visitors would like from a redesign before you begin.
8- Respond to feedback (both before and after relaunch) and make changes if needed.
Check this article out. Bottom line is don’t do a do over if it’s not needed; because your users get used to you’re design and might not be willing to readapt to different design. Think of it as a new upgrade for a software, a lot of people are not willing to go and do an upgrade, just because of the fact that they are already used to work with the old software. Some people are still using Win95 instead of XP why?? Same reason!