They are absolutely pivotal to the experience. The game would lose all its personality without them. So it makes sense to bundle a pair of Helghast goggles with Killzone 3's special edition. The collector's/limited edition - which was accidentally uploaded to Killzone.com and captured by PlayStation Lifestyle - also includes a gift voucher and "Blood & Thunder" map pack download voucher.
You know, depending on how much they want to flog a pair of Helghast goggles for, we'll be willing to bite. We'll wait for the official announcement, mind. Good grief — we hope the goggles light up! It wouldn't be the same if they didn't.