This Wall Street Journal article
provides some things to consider for married couples about how best to separate and combine their finances including bank accounts, retirement accounts and property. Here's one interesting example of what one couple did for their home and brokerage account:
A few years ago they had an attorney place their home and brokerage accounts in a revocable trust and named the trust the beneficiary of their retirement accounts. The idea was to allow for the easy transfer of assets and to save on probate costs and estate taxes.