I've been thinking about MtG synergies in an post-M10 pre-rotation world. Here's a few ideas I'd like to play around with (and see others play around with).

Duress + Memory Plunder

M10 gave us the perfect, low cost, enabler for Memory Plunder with Duress. Duress is, recognisably, one of the best discard spells ever printed. In terms of Memory Plunder, what's great about Duress is that it hits exactly what you need, without the life-damage drawback of Thoughtseize. It should also be noted that Duress can hit Planeswalkers that are in the hand as well, although Memory Plunder can't. Although there are quite a few great targets for Memory Plunder at the moment (for instance, Bituminous Blast, Maelstrom Pulse, and Cryptic Command), I'm sure there's someone out there who's going to live the dream of first-turn Duress hitting Cruel Ultimatum, followed shortly by a forth-turn Cruel Ultimatum at instant speed. That's gotta be a brutal kind of punishment against 5CC in the early game.

Master Transmuter + Ethersworn Shieldmage

Ok, she's slow to get on the field. Acknowledged. But once she does, surely in Standard right now she's one of the best combo enablers. I like Shieldmage because you can easily play him unto himself to protect your Transmuter, plus his CIP ability is really brutal against aggro decks. Of course, there's a lot of other great artifacts to flash in, most notably Darksteel Colossus, Inkwell Leviathan, Sphinx of the Steel Wind (who makes Baneslayer Angel look like a fluffy bunny)...

Silence + Meddling Mage + Ethersworn Canonist + Pithing Needle + Mark of Asylum

Control is dead! Long live control! I think we've entered an era where control is no longer counter-magic control, but a more pro-active control. You've got cascade? I've got Ethersworn Canonist. You've got Ajani? I've got Pithing Needle. You've got Volcanic Fallout? I've got Mark of Asylum. I think control is a totally viable strategy, especially with defenders such as Wall of Denial, Wall of Frost and Wall of Reverence, and several two mana counterspells floating around in a creature-heavy metagame. Plus there's still a little card called Cryptic Command that's available.

Tezzeret the Seeker + Fabricate

Whether it's recognised or not, blue/white artifact control has the single-best tutoring in standard at the moment. Whether you choose to go with Ranger of Eos to grab a couple of Court Homonculus, or use Tezzeret and Fabricate on the same turn to grab Master Transmuter and Darksteel Colossus, or Faerie Mechanist to dig for the artifact you need. Any game you survive the round with Tezzeret in play and a Fabricate in hand, you've got to be able to win the game.

Sen Triplets + Time Sieve + Open the Vaults

Okay, everyone loves their quick Time Sieve + Open the Vaults + Tezzeret Ultimate combo. But I'm a cruel, cruel person. You know what I want to do with multiple turns? Play my opponent's cards! Dropping a Sen Triplets before going off with the combo is a great move. After all, your opponent can't counter anything you do on your turn. And if you have multiple, endless, turns? You get to play their hand, build your board, and crush them with your sandled feet. Or something.