My advice for you is similar to what I did when I was a summer during a tough economic time (note: I was the only one in my summer class to get an outright offer...others were on "hold."). Keep your head down. Work work work ... like a dog. Yes, you should take part in social activities But, if there is a non-command performance and you have a project to finish...finish it. It would be helpful to get in early, stay late, have people view you as the type of person they would want to work with longer term. We often ask, is this someone I would want to work with at 2am if I had a deadline that took us into an all-nighter..is this someone who I can spend time with...and who I can trust to put the time in, not blow stuff off, and do a solid job?
Yes, this summer will be tough. You need to show that you are tough (but pleasant), bright, dependable. Double-check your work, be enthusiastic about your projects. If an important partner invites you to watch his or her depositions, negotiations, etc. - GO. Look interested. Help with whatever is needed. You need to make even more of an effort to show you are a STAR. The fun is over, it is time to bear down.