Charla Bilinski has an interesting article on Catholic Exchange today on Breathing Space about having siblings share a room. Her boys have reached an age where they no longer want to share a room.
My boys used to have their own rooms. Isaac was the original non-sleeping child, often up for hours at a time in the middle of the night - not crying, just up talking to himself in his crib. It wasn't until he was over 2 that he began sleeping through the night with any consistency. We didn't want him to wake David who was still pretty little himself so we just kept them in their own rooms.
Once Isaac was moved into a bed, however, his nighttime wanderings often took him into David's room. One night, they decided that they wanted to sleep in the same room. Both said that they didn't want to be lonely at night anymore. It worked for us. Within a week, Bernie had claimed Isaac's old room for his at-home office and there was no going back. The boys have had bunk beds for over a year now and love it. Sharing a room works for them because they are both boys, so close in age, share the same toys and even some of the same clothes. I imagine there may come a time, however, when they will get sick of sharing and want their own space, at which time we will need to reevaluate.