Bornakk somewhat answered these questions in a forum post yesterday, if only by saying that they would be answered in the next Blizzcast. Of course, first of all, it's good to hear the word "Blizzcast" mentioned again. It's been quite a while since the last one, and a lot of us have been watching for it with bated breath. Secondly, it should be interesting to hear the developers talk about the badge system, what worked and didn't work, and if it's a good enough system to carry over into the next expansion.
I do expect we'll see the system in some form again. It's a great way for people to gather loot at their own pace, and it serves as an easy to implement secondary reward system for the Heroics. What I do think might happen is a dialing back of the quality of the loot, and possibly nerf the badge drops from 10-man dungeons. The 2.4 badge loot, while closing the gap between uber and casual gearing for WoTLK, might be considered just a bit too powerful. With the new season 4 ratings requirements, Blizzard seems to be genuinely moving away from the "welfare epics" stigma, trying to make higher end gear more of a genuine challenge to get. Given this, it seems they'll likely impose similar requirements in the PvE arena. Thus, I would expect them to dial back the power of the badge loot a bit, perhaps always keeping it at the level of the latest 10 man loot or slightly higher - strong enough so that people can customize their gear and get a few drops to keep them happy when certain items just won't drop, but weak enough that 25-man raiders still have reason to keep downing bosses.
By the same token, the fact that many people can get 22 badges easily with a quick 3 and a half to four hour Karazhan clear may inspire them to dial back badge drops in the 10 man dungeons as well, both to encourage running of Heroics and to make badges a little bit scarcer so that they can feel more comfortable with badge loot requiring some amount of work. Of course, it goes without saying that we'll see some new badge type -- it would hardly do if you could buy level 80 gear with level 70 Badges of Justice.
Whether my predictions are close to the mark or not, hopefully we'll know soon. There's still no word on when the Blizzcast will be coming out, but when it does, we'll be sure to tell you here.