Ore at 20g/stack?? Holy cow i'm jealous. i'm on a high pop realm as well and it's still going for 40-50g/stack easily. Although part of that may partially be my fault since I am buying everything up that is 45g/stack and under. I'm still able to more than double my money with the elementium shuffle and using ShuffleBuddy is not hardly any work at all. I think this is definitely a quicker way to make gold than straight up mining it. I've been buying the ore of 4-5 different botters on my server. So I'm basically still making double off of what all of those guys are making from that ore.
As for stockpiling, I wouldn't get to excited over it. Stockpiling is more about moving your liquidity into assets rather than in gold to avoid inflation that comes with every xp. It's more about keeping your same gold value relative to its buying power. Sure, you may end up making gold, but that's never really been my primary intention of stockpiling. As for stockpiling, try buying elementals, enchanting mats (except for Cata mats), etc on the cheap as these will likely rise in value in MoP. And contrary to what you said, many people are hoarding pets right now. Despite the fact that they may be account bound, there is still an anticipation of increased demand.
You can also use this time to level alts. Make sure you have a gatherer ready to go come MoP since the first month or so will be HUGE for gathering profs. After that, the shuffle will be back. So do you have a Max-ranked enchanter/jewelcrafter/alchemist ready? If not, you should take the time to level these profs now. Come MoP, you'll be wasting valuable opportunities in this regard if you aren't prepared and with all the new pandas, powerleveling a profession will likely cost you an absolute fortune in the mats, so doing it now while mats are still at reasonable prices would be the smart thing.
