Hemblem,
Although you're redesigning the site, I actually don't recommend using a 302 redirect during the 'redesign' process, as it can have disastrous effects on search engine rankings. I would prefer that you keep the current website up and running: and then 301 redirecting the appropriate pages when the site is ready to go live.
I realize that you want to do, but I have seen too many websites have problems getting things straightened out with the search engines to do what you're suggesting.