I'd weave thick ribbons or fabric strips vertically in fun colors.

You can make this look great by buying two large pieces of cardboard and cutting them to the size of the headboard. Do the same thing with two large pieces of foam. Attatch both to the metal.

Then, buy some earthy boho fabric that complements your bedspread and cover the foam and cardboard with it. Voila! A pretty, soft headboard!

Or if you're not into the DIY thing, just get some floaty scarves and tie them to the bars so they cover up the harsh metal. Good luck!

I'd recommend painting it as well. I think structure can add sophistication to an all bohemian palette. I had a similar experience with a brass headboard I inherited. I spray painted it a bold blue, and it really pops and somehow works with all of my boho-anthropologie inspired stuff. The ribbon idea is great too, and if you are really college dorm/bohemian inspired, maybe weaving a strand of white twinkle lights would be fun.

I like the idea of a fabric panel that would fit over the headboard...

Paint it white or light yellow and put these pressed flower stickers all over it:

http://www.custompaper.com/Shop/Stickers/flowerstickers.html

I agree with painting it, then adding some sort of decoration to it. Maybe string some lights around it? I know Ikea was selling a string of flower-shaped lights.

The structure of the headboard sorta reminds me of a trellis in a garden. Maybe you could play with a concept of it being overgrown with some kind of tasteful flowers or ribbons or baubles.

Maybe also drape some inexpensive tulle fabric or lace to in dramatic forms to cover up the empty space under the bed.

You could put a cute floral curtain on it. Or drapes.

I really don't know. But I lovvvve that bed! LOL So cute.

Paint it then simply drape fabric (quilt, rug, etc) in your favorite patterns and colors over the headboard and footboard. Pretty and functional too!

My idea was like sabaum's. I was going to say hang antique quilts and blankets through the rungs- like a quilt holder. (After you paint it, of course.)

My first thought was also to drape fabric all over it.

My other idea is to figure out where the bed will be and figure where each square will be. Then paint each one with a different floral theme to go along with your own style. This idea is almost similar to an earlier post from June... http://casasugar.com/1732062

My suggestion would be to select some pillows that you like and tie them to the top rung of the headboard. If they're large enough, they might cover the metal almost entirely. I've usually seen this done with a curtain rod as a substitute for a headboard...you mount the rod to the wall and hang the pillows from it.

Large square pillows obviously work best. I did this once with oversized European shams from Pottery Barn...they already have ties on the sides, so I didn't have to alter them (just stuff them with pillows from JoAnn's or another craft store). Dining chair cushions often have these ties already, too. Otherwise, you could always sew ties onto any pillow you liked...

My first thought was the weaving as well!

Maybe take painted wooden fence posts and stagger them behind the board? Paint the metal headboard a matted white--like a trellis (as others said)--and weave flowers around it?

I don't know. Good luck! Post the results!!! :0)

This idea is kind of out there, but do you need the headboard? If not, you could use some bolt cutters to separate it from the frame at the height of the matress. Then, you can hang whatever you want behind/over the bed as decoration (fabric, curtains, artworks, etc.)
Use a bed skirt to hide the legs and allow your comforter/blankets to cover the rails at the foot board. Voila, no longer modern!

You could always hang a quilt or blanket over it. If you do that you always have one handy if it gets extra cold at night.