You know, I've actually put a little thought into this myself. (Warning: long post ahead!) I mean, what if Hasbro decides to do something really stupid, or what if Disney buys it up and puts an end to G4? (Or what if we just want Derpy back really really badly?) Would this actually be possible? I think that, crazy as it sounds, it would be. (Not practical, mind you, but possible.)
First, how much is the MLP franchise worth? I recall hearing Hasbro sold the gaming rights (and then bought them back) for around $100 million, so that puts an absolute lower bound on the value of the franchise. (Since the gaming rights to MLP isn't going to worth more than all of MLP.)
On the other hand, Hasbro has roughly $4 billion in assets. Because (as far as I know) Hasbro is the sole owner of MLP, that puts an absolute upper bound on the value of the franchise. (Since Hasbro's total assets (not their net worth, just their assets, which excludes liabilities) are worth more than just part of their assets.)
So, we can be almost positive MLP is worth between $100M and $4B. Let's just do a geometric mean and say it's around $650M, because I'm not a good pundit and this is all just a rough estimate.
So, $650 million. That's quite a lot of dough. Now how many bronies are there?
Estimates vary widely, but I believe that last Brony Census calculated that the population was on the order of 10 million people. So if each and every one of us ponied up (hehe, pun) $65 or so, we could indeed buy the franchise outright.
However, this scenario is unrealistic. Every brony? Yeah, not gonna happen. So then, suppose less than 1% of us actually decided to put some money into this. In that case, we'd need around $10,000 each. And that's a lot of money to pay, considering each purchaser only gets 0.001% of the franchise.
So, conclusion: it's impractical, it's unlikely, it's implausible, but it's not impossible. And that's what amazes me: If we really needed to, we could actually freaking do it.
And as for what to do afterwards, I too would keep the original animators. I'd say give them near-complete autonomy, let them make the seasons as long/short as they wanted, etc.
Okay, my comment is almost as long as the original topic post, so I'll quit yapping now.
Edit: Does anyone ever read the tags? I do!