Hello there. I applied for a Spouse Visa using my old passport in my maiden name. UKVACS didnt require me to renew my passport as it is still valid until 2010 which is a year after my Visa expires. We chose not to renew my passport using my husbands name because we were pressed for time and DFA was pissing us about with so many requirements. A word of advice: once you get married and you get the marriage certificate, immediately request for a Marriage Certificate on "Official Paper" from NSO. They are so laid back there you will probably get the one in official paper after a month. You cant file the Spouse Visa Application until you have it. Congratulations on your forthcoming marriage. God bless...