Dave Winer: Ye-hi, the outliner market on the Mac is coming back to life. Here's a really interesting line from the Omni website. “Multiple columns per row a first for any outliner that we've seen!” Wow. Takes your breath away. MORE didn't do multiple columns, but InfoDepot did. It was their big feature. Frankly, imho, if you design it that way, it's more of a spreadsheet than a thinking or writing tool.
Users beware, one of the lessons of the last round in outlining is that you don't want your ideas locked up in a proprietary format. That's why MORE had lots of import/export capabilities. Before you commit to Omni, ask them to clearly state that your work won't be locked up. OPML is the perfect solution for interchange between programs that understand hierarchies. Keep the market open. It's good to have competition. One more thing, be sure they have a good scripting interface. It's important