Mine are 2.6 and absolutely killing me right now. We are surviving though, apparently, so my advice would be:
You probably won't be able to do a lot of the things singles do, so try really hard not to feel guilty about it (same point neversleepagain made) You will probably feel like a shit mother for not always getting them to all the classes and activities and stuff that you would like to, but you are not. Of course, if you have someone else around to help this probably won't be the case.
They will start to interact, eventually. I got so fed up of people asking "Do they keep each other entertained?" when mine were babies! No, of course they bloody well don't! But now, having turned 2, they can actually talk to one another and chase each other around and have a good time together.
However, they will fight. And fight and fight and fight and the hardest thing is knowing how much to intervene and how much to let them sort it out together. I'm still working on that one.
Oh, and a little positivity to finish off with:
The sweetest, most wonderful thing ever is hearing them saying each others' names. It is the best.
(I still want to kill mine today though) 