Good luck with your adventure, it will be a good move for your kids, but that's why you want to go surely?
Will you want to come back, probably. Homesickness can be a terrible thing and we all "big up" the smallest things and make them more important than they ever could be when homesick.
There is an opposite, My wife had a friend who migrated from the UK to the USA 14 years ago and only came back once. Her visit confirmed for her that she didn't want to come back to the UK again and she has stuck to her words.
SKYPE will be the way to go, as previously stated, and with technology improving day by day, it will only get better.