In my oppinion, design changes should be subtle and be done over time instead of a overnight make over. The reason being people need t get accostomed to the new desin if it changes uddenly and in essence, they will be re discovering your site.

I would suggest little changes amounting up to the planned end design, he thing is, design doesn't just stop, its a thing that evolves. Take the Windows logo for example, it essentially is the same object yet it isn't.

The reason we recognise it is because of the change over time and it will probably change slightly again.

Hope this helps.
Regards

Hi there
if it ain't broke, don't fix it.
if you are considering a re-design, get a free consult first, I'd be happy to look it over for you.
sometimes a redesign can really increase sales, especially if you have old graphics, spinny things, 40 different fonts,etc
but other times, leave well enough along

you can do a redesign without taking your site offline and can announce a new design coming soon on the old site. Depends on your site type.
Linda

Web site redesign can solve old usability problems while introducing new ones. What we do is take your present website, use what you and then create a much better version, with the newest scripting, coding, flash animation, graphics and CSS, that will be compatible for most browsers.