Recently married--what do I need to do?

I've been busy as heck ever since the wedding (June 23) and I haven't notified anyone or done anything.  I didn't change my name in my passport or with my banks, as I really just don't want to start dealing with that trans-atlantic hassle, and buying a new passport, until I have finished my PhD and have a little more time to think.  We need to get our marriage certificate from his parents' house before we can document that we are married to our respective banks and that sort of thing, and for the moment, I'm just letting it all slide.  We are going to apply for my FLR next month some time (my student visa expires at the end of December), and aside from being extremely poor I'm not too worried about that.  Once we are in a better financial position (a few weeks?) we plan to draw up wills, get life insurance, and all that kind of stuff.

Is this a mistake?  Should I be doing something more "official"? 

I'd say getting married in the first place was pretty "official", hehe. Congrats!

As you're not obligated to change your name at all, when you change it is up to you.  Your FLR will be issued in the name in your passport, so if you want it to have your married name on it, then I would suggest you get a passport with the new name on it ASAP. Apart from that, you can do things at your leisure, pretty much.