Bower has kindly sent me about 700 seeds from her chard crossing experiment. Look for her thread for details.

I'm offering seeds to anyone who would grow it out this year. Otherwise, seeds will be distributed in the next MMMM swap. Chard is a biennial, so anything planted this year must be overwintered, and next year's plants will go to seed.

Here's a link to the thread
viewtopic.php?t=4321

And in my experience they go to seed mid spring of the second year if that helps people plan in a milder climate like mine. They won't take up a full two seasons of space. And if the chard is good then you can keep harvesting off as they bolt. The bolt is a slow process for us here and it doesnt turn bitter.