It definitely started out like that, but it all ended very differently...
I had all but given up on PuGging Kael/Vashj for the vials, but out of habit I stuck myself in the LFG channel for SSC, TK and Hyjal. As I hauled ass around Redridge collecting spider legs and goretusk snouts for a Cook NPC, I got a /whisper:
"Want to come to TK? Only Kael left"
Sure, I thought. Get locked into yet another TK instance with no chance of even getting loot from easier bosses, and waste my night wiping. They must have wiped, otherwise why would they be asking for more DPS when they're at Kael? Don't join!
/whisper Raid Leader: "Are you likely to get Kael down, or no?"
"Yeah, we worked out the kinks and should get him this time"
A moment's hesitation....."OK, invite"
Of course... just when you least expect it: Kael down, and one-shot. Woot!
In my elated mood, I joined a raid on Thunder Bluff. Didn't get anything out of it (not even 5 player HKs), but it inspired me to head to Orgrimmar (alone) afterwards and get 3 more achievements done in quick succession:
On another note: Feign Death and Shadowmeld do NOT work on City Guards. I ended up with an awfully large repair bill last night... but it was SO worth it!