Ryan Wagman (@RAWagman) and I recently wrote an ESPN.com article on trade deadline fixes for each of the Atlantic Division teams. Check it out here if you have ESPN Insider, or here if you are a member at HockeyProspectus.com. For the other divisions, there are links on the right hand side of the ESPN article.
Disclaimer: we finished the article before the Pens' flurry of trades. We picked Adrian Aucoin for the Pens, suggesting the Pens biggest need was a depth defenseman. Since then the Pens acquired a different defenseman, Doug Murray, so that sort of coincides. Of course, the Pens did some other stuff too.