Maybe my children are just well adjusted or perhaps they have just not been coddled. When I decided to take a short three night trip over a weekend with my mom, two sisters (who also left their children behind), and my 81 year old aunt, there was not so much as a sniffle from them. We had just gone on a family trip in March of that year and in May when I told them I was going to Disney with Gammie and that I would take them again next year they were perfectly fine with it. I called them each day.
Now, I will say even though they didn't cry, I did lol. I bawled like a baby the afternoon we were there because it was the first and only time that I have ever gone anywhere without my children. It was a nice getaway. Will I likely do it again? Nope but it was nice while it lasted. My advice is to be open and honest with your children, as that is likely how you would like them to be with you.
As for the posters who said that they couldn't fathom someone not telling their kids the whole truth because they would wonder what else you weren't telling them. Do you not tell your children that there is a Santa, Tooth Fairy, or Easter Bunny? Seems to me that may be a little untruthful, but I am sure your children recovered. My way is to tell the kids about the trip beforehand, but someone else may find it easier to do it another way. To each his own.