As for Maro, I think he's a great designer, and that "restrictions breed creativity" is misinterpreted and abused by the community at large. His examples are always things like "we need a black common that supports both Orzhov and Dimir" and, well, you know. Lost is the dialogue is usually the fact that creativity (if present) doesn't necessarily convert to fun. I can think of lots of design restrictions that cause you to have to be creative, while still forcing miserable gameplay.
Oh, the restrictions breeding creativity thing. Yeah that's okay.
The trouble with him is, you have to read everything he says keeping one fundamental thing in mind:
he wants you to buy product.
That means that in 2008, you will see several posts explaining why the Untap symbol in Shadowmoor is the most brilliant, innovative thing. It's hip, it's hot, it's hopping! It's gonna save your games
and slice your bread. You're going to experience the BEST GAMES OF MAGIC EVER now because of their cool new creative mechanic!
2 years later (about the amount of time it takes Shadowmoor to rotate out of Standard,
coincidentally), WotC finally admits that Untap was a terrible failure. Players figured this out much sooner, of course, but official channels couldn't admit their mistake until SHM was mostly finished up. But you should buy their new set because it's brilliant and fantastic and solves all the mistakes they've ever made in the past!
There's a lot to be gained from reading MaRo posts, but you have to sift through the hyperbole and keep in mind that whatever he says about mechanics that aren't yet 2 years old might be all fanfare and hype.