Here is a good post from FederalEvidence blog.
Inadvertent Disclosure Under FRE 502(b) Not Shown By Failure To Assert Privilege Promptly
Court denies motion to compel return of e-mail message after concluding the disclosure was not inadvertent under FRE 502(b) since defense counsel “had ample opportunity to discover and assert the claimed privileged status of the e-mail” and failed to do so, in Clarke v. J.P. Morgan Chase & Co., No. 08 Civ. 02400, slip op. (SDNY Apr. 10, 2009)
The courts continue to apply FRE 502(b), enacted in September 2009, on the issue of determining whether disclosure of privileged communications was inadvertent. See generally President Signs New Attorney-Client Privilege Rule (FRE 502).
Under Mil. R. Evid. 1102, this rule will become effective mid-2011 for military cases unless the President takes action.