If you are wanting to maintain rankings then a whole new domain would probably be the worst thing to do.
Are you looking to just re-design the existing pages leaving content and page names (URLs) alone? Or are you changing all the page names (URLs) and the content or ...
If you you are just changing the 'look' of the existing pages then any SEO hit shouldn't be too bad if there is any.
In fact, if done with SEO in mind it could even help if it sorts things like page load times, stickiness, click through rates, visitor generated backlinks (due to being a nicer site) etc.
After that, if the site is changing I expect the idea is to improve conversions, in which case even if there is a small drop in visits due to lost rankings this would be more than made up for by the better conversion rate.
In the end, all change is a risk and all you can do is plan accordingly.
Last edited by Kevin H; Sep 5th, 2013 at 04:08 AM.
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