Google Mega Sitelinks Live
Mega sitelinks, jumbo sitelinks, super sitelinks.
Call them what you will, the test that Google has been running for a week or so on expanded sitelinks appears to have gone live.
All my searches for what Google will naturally consider to be a brand term are now showing something like this:
Effectively, what used to be 8 text links is now 12 (or in some cases 6) mini search results, with a title taken from the internal links on the site in question, a URL and a snippet generated in the normal way from the body content or meta description of the page (albeit a much smaller snippet than a normal result).
Here's an example with 6 super sitelinks:
This seems to have replaced Google's relatively brief fascination with simply listing multiple pages from the same domain (something that always felt slightly wrong to me), and I think it's a marked improvement for users.
POST SCRIPT: Various Greenlighters have since pointed out examples of this with 2, 3 and 4 sitelinks, so evidently Google has no fixed amount of these to display.