How do I decide whether we should file separately or jointly?
As other posters have said you don't really know until you sit down with the taxes. In most cases there are dedcuctions that phase out much earlier if you file separately so it's not worth it for most couples (with the exception of Ohio, as someone has mentioned).

Depending on your circumstances you may owe about the same, a little bit more, or a little bit less in income tax than you did when you were single. It's a hard thing to budget for.

But what other potential benefits or considerations should a newly married couple look at?

Try asking at the Family Fool board at http://boards.fool.com/Messages.asp?bid=100147 . That topic has come up before I seem to recall.

- Megan