Lots of changes...some big, some small...where to begin...
As mentioned by others...Stormstrike Horde AV queues went from often upwards of 2 hours (2h11m my longest) to < 5 mins any time I've queued since the patch went live. Right there is a big, big kudos to Blizzard.
As far as the Horde side of the AV changes...well...hrmm. Let's just say I played AV as Alliance long before I ever rolled my Shaman. Frankly, it wasn't until I got my Shaman into AV that I fully grasped just how much of a starting advantage Horde really had in terms of distance from entry -> Van. Of course, not knowing this didn't give me an opportunity to QQ as Alliance (what a shame), but it also gives me no sympathy whatsoever for the wee lil hordlings entering their first AV since the patch with, "OMFG they nerfed AV we're so far back omfg omfg omfg!!"
The strategy seems to have changed a bit. And with it comes the hotly contested, "I know better than you how to win this so do it this way" followed by, "u r teh nub do it the opposite way or we'll lose!!!" Oh, and of course, the typical transition (still ongoing) of teaching people that warmasters left in a boss' room give him a substantial buff to HP and damage. We won most of the runs I did tonight, which made me a happy camper...finally got my S1 offhand (the 1x each mark for 312 honor is brilliant, too).
Edit to add: Premade queues seem to have gone to hell. I joined two premade groups over the last couple of days...neither of them set foot in a BG because it took so long to get in. Queuing solo, a person would be into the BG in 3 minutes or less...queuing as a group, I left both groups at 15 minutes and still counting to get into BGs showing as 1-3 minute average waits. I've been told that the queuing system is matching premade vs. premade now, so that you don't get a full S2/S3 premade dominating relentless succession of mixed PUGs for three hours. Suits me just fine if that were the case, but that's just a rumor.
Finally, despite rumor to the contrary, patch 2.4 did nothing to reduce the number of self-serving, ignorant, argumentative retards queuing for BGs. Nevertheless, the queue time reduciton on AV alone has everyone on my realm jumping for joy.