While I originally thought that these were going to be the next Adventurer's Guild items, you can get these all on eBay for relatively cheap. They are actually almost EXACT copies of the pdf versions (which have full art), but these have covers. Printed in black and white, softcover, the adventure quality playablitity-wise varies (Key to Phantom's Cloister looks great, but its the first part of a 2-part series where the 2nd part has never been released). Printing quality is good, on nice, glossy paper (makes you sad its only in b&w!). The only one that is slightly tricky to get ahold of is Extermination (which came in the "Con In a Box" with the Fist of Emerikol die, which is a pretty neat item if you can get your grubby claws on one).
I find them kinda neat... they might get semi-rare later on, but all indications are that
WotC is printing tons of them (they are promo items, but easily ordered by any gaming shop). Check out this page for more details on all the promo goodies
WotC is releasing once a month as part of these packs (the adventures are just 1 item).
http://www.wizards.com/default.asp?x=rp ... ignseasonsGet them while they are cheap (who knows if they'll stay that way?). They are the only official adventures being released for FR right now, which puts them in an interesting position. The pdf versions are rather hard to find too... I've been trying to get my hands on them since the campaign launched a year and a half ago, and only this week managed to find somebody who would mail them to me in return for some Living Greyhawk modules.
On another note, WotC has all but officially announced that the next "D&D Campaigns" series will be set in Eberron. They'll probably make the announcement at GenCon.
(Feel free if you have any more questions, I've been picking these up as they've been released).