Thanks
Until about a month ago, our company was mycompanyinc.com.
Last month successfully grabbed an expired domain that was mycompany.com.
Immediately set up a 301 redirect from old to new domain.
Two weeks later, old domain disappears from google,
and new domain is still not listed on google. Ouch!
Regret not first doing 302 redirect for a couple months,
then switching to 301 redirect after new site is well indexed.
However, when you are making a permanent move, the new domain name is not showing with a 302, even though the content is taken from the new resource. The handling of 302 redirects that go to a different domain is a very, very sore spot for many webmasters because they have had their ranking pages "stolen" by a domain name they do not own, due to this handling of cross-domain 302 redirects.
To see the new domain name in the SERPs (and not just its content) it still takes a 301 redirect in my experince, and that can mean a wait with the way new domains are currently handled. I've had better results with a page by page meta-refresh, but that has very real limitations on large websites.
The biggest hope is that the SEs will sort all this out very soon. But no matter how or when that happens, I would still go with a 301.
And - make sure the config is right for the new domain, with all factors properly migrated, so there are no obstacles for spidering the new addresses.