301 doesn't permanently "delist" your domain. If you later decide to do something with it, remove the 301 and it will come back with whatever new content you put on it.
It all depends on what you're trying to do: Are you trying to tell the S/E's that whatever was previously on domain1 (including incoming link juice) has been moved to domain2? Use a 301. Are you trying to tell them that they should TEMPORARILY look at domain2 instead of domain1? Use a 302.