Elliot is going to look into inner-blocks later on this year, my guess is Nov/Dec… In the meantime what I have done to create my own columns, have each column in Accordion fields, and for the content of the columns use the WYSIWYG editor. I can get away with it, becaus so far all of my 41 blocks, are conversions from my preexisting shortcodes. And because TinyMCE displays the button to generate the shortcodes, it works pretty well. Also because I’m using accordions, I’m actually building the columns vertically, which give me more room to edit things. The biggest drawback is that if I want to change the layout (ie: from 3 columns to 4 columnjs), I have to delete the 3 column block and start a new 4 column block…
