Bookshelf Headboards

Is it always a bad idea to mix headboards with shelving? Despite our discomfort about things constantly being knocked off the shelves, we really like the notion. Kept well-edited, the shelves would provide lots of surface area for the night's read, a lamp, and other bedside appurtenances.

And we like the look, to boot. Some successful examples of mixing the headboard and shelving function:

1 from an apartment designed by New York's Studio g&a.
2 Dwell Studio via Good Questions: Bookshelf Headboard Options?
3, 4 Better Homes and Gardens
5 a single floating shelf on the headboard, Canadian House and Home via Urban Sardines