The Textron case on work-product privilege centered on the company's tax accrual workpapers. The memos are a normal part of a company's financial statements, showing the analysis a company (and, often, its lawyers and accountants) used to calculate the reserves it sets aside for uncertain tax positions, which are common in tax law. In laymen's terms, tax accrual workpapers embody that math-class platitude to "show your work."
Companies handle tax accrual workpapers differently, and, especially in light of Textron, some might want to reevaluate their policies. But it's a tricky balance to go into enough detail without destroying privilege.