The Supreme Court decision that issued last week of general appellate interest was the first opinion from Justice Sotomayor, Mohawk Industries Inc. v. Carpenter, 08-678. http://www.supremecourtus.gov/opinions/09pdf/08-678.pdf. The decision was unanimous (with a concurrence from Justice Thomas).
The issue was whether the grant of a motion to compel what a party deems privileged information is immediately appealable under the collateral order doctrine. The answer is no. While you might not be able to unring the bell in a practical sense, you can in the legal sense, after the fact: the court can remand for a new trial without the use of the information. Justice Sotomayor also noted that other potential avenues for interlocutory review may obtain in the right circumstances: a certification under 28 U.S.C. s. 1292(b); mandamus; or appeal of defiance under F.R.Civ.P. 37(b)(2) or a contempt ruling.
How does this compare with Maine law? There is no interlocutory appeal for a motion to quash based on privilege – you must defy the order and be held in contempt. I n re Willoughby, 487 A.2d 636, 638 (Me. 1985). See also Lewellyn v. Bell, 635 A.2d 945, 947 (Me. 1993).