Frankly I think distance is a pretty weak excuse these days. My PIL live in WA, we live in QLD. DS1 has a great relationship with both of them because we use skype to call them regularly (and they call us).
DS2 will grow up knowing them really well too because we already maintain good contact because of the skype set up for DS1.
My family don't do the same however, and I find that really sad because they're in VIC so really they're closer but for some reason they contact us less regularly and almost never on skype even though they have it.