I was wondering, I did a 301 redirect from my old domain to the new one. I have Both Site maps for the 2 domains on Google Webmaster Tools. Should I keep both or delete the old domain account? I was thinking that leaving the old domain, the spiders will crawl the old domain and then be 301 redirected to the new one? Is this correct?
Yes it's true, spiders will follow the link returned in 3xx response, so you should probably wait until your new domain will be crawled, and then you can delete the old domain.
yes its possible but i don't think they will be redirected but users that came will be redirected and you will get users from older links presend in search engines!
Keep it. There will almost certainly be old links to the old name that you don't want to lose track of.
i think you must one use of your domains. if you use 301 redirect , everythink (pr, indexs) will pass the new domain
The Google Bot will be redirected to New Domain. There is no point of keeping the old site map if all of your pages being 301ed to the new site as old pages will go in Supplemental Index as soon as Google detects 301 on them and updates primary index with your new site's pages. (Keep the old pages on server though)