Sadly, I don't see Epic support in our future, but honestly, amidst all the blog entries and Chris Perkin's DMing column, we know about as much as they do on the subject.
I'd be willing to contribute to an Epic source book once I've finished Epic. My parties are still level 21, though. I've kind of taken the game pretty far out, though, so I imagine their capabilities are more along the lines of 24-25.
For one, I bend the rules a lot thus far, both to create unexpected, interesting, and actual challenges. I just recently ran a session where the minions started off pretty standard, but each subsequent generation of minions spawned to replace them became immune to the damage types that killed their predecessors (even physical damage). That got interesting really quickly, and created a fun, strategic, and suspenseful combat. I use auto-damage auras, blindness and invisibility, add-ons like Shadowfell's Corruption deck, healing surge loss and death save failures, and lower hp/higher damage monsters.
I've balanced this by giving my players a LOT of control of the game setting itself, representative of their power and resources. They're all in control of substantial resources, cities, kingdoms, worlds-spanning faiths, or tied to massive power stores, like my Psionic characters basically tapped into the collective consciousness of every single mortal being in the planes. Similarly, their responsibilities and potential are huge. My Divine power source characters are currently involved in plots to rescue their dying gods by fusing the sparks of other divine entities to their own. Some are even considering trying to subsume primal spirits, even aberrant entities, in efforts to sustain deities and wake them from their comas.
That leads to my next Epic change, the idea that at this point in the game, every player has their own agenda, interests, responsibilities, addictions, weaknesses, and ideas on what should happen by campaign's end. Those Divine characters I mentioned above, they're not above fusing their gods, more or less killing one and converting the divine portfolios over to the other. On some level, they're working together to kind of keep an eye on each other.
For a group this powerful to work together consistently, the campaign provides an Armageddon scenario that must be stopped somehow. That keeps everyone civil and cooperative, and challenges their personal beliefs like any round, dynamic character should, but if and when the apocalypse is averted, and all the power of the universe is on the table, I full expect many of the PCs to turn on each other, or divide into factions, perhaps even PvP. Not that every Epic group should be like this, but I push the idea that they should have wants and needs that stand opposed to other party members, secrets, cards they play close to their chest and as Epic progresses and they see the opportunity to nudge things in their favor, they do so. It's making for a great experience thus far, some being swayed into a more lasting alliance, others positive they can't trust so-and-so with this sort of power. They're kind of like their own junior pantheon.
And maybe lastly, for as powerful as the PCs are, they are NOT the most powerful beings in the setting. And they know it. They have their power and influence, and together they are amazingly strong, but I've set up a good number of villains and competitors which also support cooperation: a gith queen from one million years in the future, commanding a fleet of Voidcruisers, who wants to see the worlds end so that she eventually becomes queen in the first place; an ancient shadow dragon with a hacked alien ship that allows for mass mind control and artificial aging, and his army of wyrmlings turned elder dragons; Void demigods come to the worlds to sew discord and strife until their aberrant sire arrives to devour all space and time; and so on.
Go big or go home, I say, hehe. And I am very fond of creatures larger than Gargantuan. That said, the game does not have a bombastic or anime feel to it. The Heroic tier and Paragon tiers still exist in the setting, and the PCs have more or less mastered them, and owe everything to them, and feel responsible for everything in them, and draw their personal strength from them. They have families, loved ones, homes, debts, and it's kept them relatively grounded (and for others kind of made them a little manic, or brooding, or straight crazy, but that's fun too).
The flip side is, they've now joined an elite community in Epic, and are reaching the waists and shoulders of their primal spirits, primordials, demon lords, and angels in height. So balancing the two is another facet of Epic we all find fascinating. To be so powerful, but so fallible still, to remain the same kind of people they were in Heroic, or to transform, even unknowingly, into a despot or merciless arbiter.
Epic has really pushed the boundaries of what I understood as D&D, and that kind of exploratory space for 10 levels is a really exciting prospect.