Update from June 20, 2011:
Apparently, they did not only ban Stoneforge Mystic from Standard, as Leonard predicted in his news piece below, but also Jace, The Mind Sculptor, effective July 1 (June 29 on MODO). Owners of the War of Attrition event deck (containing two copies of Mystic) may only still play the deck if they stick to its original out-of-the-box card list. This goes for paper only since the event deck never saw the day of light online.
The full ban/restricted announcement by Wizards can be accessed here. Someplace else you can also read about Wizards’ full explanation and reasoning behind the ban (by R&D Director Aaron Forsythe himself).
On a side-note, Frantic Search has been banned from Pauper coming June 29 rendering the popular Frantic Storm decks more or less impotent.
Yes, I did it. Just a few minutes ago, on Magic Online (or MODO as we call it), I sold my playset of Stoneforge Mystics for a little over seven tickets each. I wanted to get as much value out of this card as possible because it is very likely that Wizards will swing the ban-hammer crushing the one or other troubling card in Standard with the release of their regular ban announcement on June 20.
To think they would ban their “highly desirable” poster boy Jace, The Mindsculptor . . . is doubtful.
And all my bets are on Ms. Mystic. To think they would ban their “highly desirable” poster boy Jace, The Mindsculptor (or even Gideon Jura whose reprint has been confirmed for the Magic 2012 core set) is doubtful.
Having little to no use for her at the moment since I have refused to play Boros in weeks, it made perfect sense. And one thing was immediately clear to me: Stoneforge Mystic is certainly not going to rise in price anymore. She has reached the high end of the ceiling a long time ago. As a result of this, skilled traders are surely dipping their feet into other waters already, and hoarding those sweet equipment cards now. Without the mystical equipment-fetcher you are certainly forced to play more copies of Batterskull & Co. in order to ever see them on the battlefield.
If she, however, does not end up being banned after all, what can we do? I know. Buying her back at little to practically no loss. Sweet!