We have?
What we saw still had a lot (and I mean A LOT) of typos, dubious ability wordings, inconsistency and was still being frequently altered in the last week of open beta.
If they take the route they took with U of T to get the book out for GenCon at all costs, M2E will be a fiasco. I don't want to see the game crash and burn because someone made a really, really poor decision to insist on GenCon. A late year holiday release would've been a far better choice.
I'm not talking about the core rule system being bad (it's not) I'm taking about quality of product. No matter how good your game is, if you release sloppy product that instantly need alteration, you are inviting disaster.