Carnival Cruises is hosting a "Bloggers' cruise" in 2008 for $599 a person. It turns out it's actually a cruise with Cruise Director John Heald, who gets thousands of hits on his blog, www.carnival.com/freedom. So I guess they're encouraging fans of his to go. Not other bloggers, per se.
On an unrelated note, my fellow writer and near-neighbor Jeff Somers, whose book is coming out in fall, has experienced the wonder of getting Advanced Readers' Copies of said book (see the blog). Since he's written a zillion things and most have only been published in small venues, it's nice to see such success.