Sync is the part we're careful with.

The private beta adds the parts that move your files between machines: real-time sync across your devices, editing a document together with other people, and the iPhone app. The person you trust most with a draft is rarely in your workspace, your company, or your toolchain. They're just a person in the world, and getting your files to them without giving the files up is the whole reason this product exists. We'd rather onboard that slowly and get it right than quickly and get it almost right. Leave an email; seats open in small batches, and when yours does, the first thing we'll ask is who you want to share a document with.

The editor doesn't wait for a seat; the Mac app is a free download, no account required. Get it here.