According to what I've read in the house rabbit society's web pages (www.rabbit.org), mom will still come and take care of them if she is able to.

The trick is not to disturb the nest itself, just peek into it. and check the little guys. Then do the criss-crossing with stalks of hay or some wild plant over the top of the nest, come back in 24 hrs and see if it's been disturbed...if so, then mom has come back to take care of the kids.