I just tried an experiment with peppercorn and lime in a summer blonde ale. I was very surprised by the result of adding the peppercorn - it didn't turn out as spicy (hot) as I thought it would. Granted, I was a little conservative with the peppercorn - I used a ounce of un-crushed peppercorn with a 5-min boil - but I can definately taste it, just not as much heat as I expected.
Anyway, I think it complements the citrus flavour from the limes very well.