WebmasterWorld members are talking about receiving Google Sitelinks, and overall, most forum members who are impacted this way are obviously happy about the expanded link opportunities. Some are a bit afraid that their sitelinks may drop off (as a few members have observed).
Others are noticing that the "algo broke." There's no specific information into how the algorithm broke but some note changes.
I had them a while now but they changed radically about a week ago. Previously, they were showing country specific subdirectories on my static content... now they only show links to country sub forums on my forum. I guess that means the algo thinks my forum has grown and is more important than the static content. Fine by me, I guess.
Moderator jdMorgan notes that Google Webmaster Tools lets you now exclude Sitelinks that you don't want. Simply go to Google Webmaster Tools, click to Links > SiteLinks, select the sitelink that you don't like, and click the "Block" link to the right of it.
Tedster notes the following changes when sitelinks were implemented:
One of my clients had a sitelink that pointed to a very obscurre page - they requested a deletion and it happened with no trouble. But that particular issue highlighted a problem with their entire "mouseover" menu system - the same menu label appeared in three different places! That one little strange sitelink has now generated a major project to re-structure their entire information architecture.
Another client has sitelinks for a single generic keyword. That's a very startling event, since there are 16 million results currently reported, and the keyword triggers many Adwords plus a Google Shopping OneBox at the top of the SERP. In other words, there are serious competitors who must be furious about those sitelinks.
In other words, these are "early bugs," as he notes.
Forum discussion continues at WebmasterWorld.