You will need a front dérailleur. You might be able to get by with the short cage rear dérailleur, but I wouldn't bet on it.
Another option is using 9-speed components (STI, CS, BB, FD). Much cheaper.
Originally Posted by z415
As for going triple, you might have to do something with the bb spindle length to make sure the chain line is good and the rings don't damage your stays, though I'm not 100% sure.
That's all taken care of with the integral spindle on 10-speed crank.