What can't Scrivener do? It manages, counts, meta-datas, sorts, highlights, tags, summarizes, stores, syncs. If you wonder, can it do that? Then it probably can. It's the Excel spreadsheet of writing applications: it can be as simple or complex as you want it to be. You can hoist bits, highlight, spellcheck, drag and drop, set wordcount targets …
Okay, there are a few things it can't do: real page layout (but that's okay, there's lots of apps for that, from Word to Pages to Open Office), and bibliography management (ditto here, just use Bookends or EndNote or Zotero). And … that's about it. And it's stable--nary a crash yet. Plus there's a lovely full screen mode.
Amazing.