In Hexion Specialty Chemicals, Inc. v. Hunstman Corp., 2008 WL 3878339 (Del. Ch., Aug. 22, 2008), the Chancery Court engages in a thorough discussion of the availability of the protection in Chancery Court Rule 26(b)(4)(B), often referred to as the "work product doctrine". After an extension analysis, the Court determined that the documents needed to be produced and the motion to compel was granted to the extent described. In sum, the Court reasoned that the investment banker involved "cannot properly be regarded as a litigation or trial consultant within the meaning of Rule 26(b)(4)(B) and … the documents presented to the court for review do not fall withing the ambit of attorney work product."
The court also discussed the "business strategy immunity" and the attorney/client privilege.
Here is a link to two prior Chancery Court decisions in this case on other procedural issues, including an important opinion on "inadvertent production of privileged material", which provides additional background facts.