I find the reports about Mattel interesting, but WotC is a very small part of Hasbro -- and the roleplaying line is a smaller part still. To me, what matters is that people who love gaming run WotC. Part of me thinks WotC might get better marketing as an independent company. Although the Dungeons and Dragons name is one of the best known brands on the planet, there has been little marketing of it by Hasbro.
Possibly Mattel might want to sell any lines that were not considered part of a core business model. However, someone would be willing to buy WotC as the roleplaing games, books, and card games are still profitable.
Perhaps the question should be if Mattel buys Hasbro and sells WotC, who should buy the company. My hope would be that it would be someone with an understanding of the company, our hobby, an appreciation for the customers, and with great skill in running a business. (Can someone link Ryan Dancey's excellent essay on why TSR failed?)
Several of the publishers whom I have seen on these boards could probably run WotC well, based on their success at their own companies. However, I imagine that the cost of buying WotC might require some companies to pool their financial resources.