I'd say Nintendo should NOT buy Sega, but if Sammy plans to dissolve Sega, Nintendo should put a bid in for IP rights, and claims to ownership of all previous titles. Those are the only two assets that Nintendo could make use of.
On another note, a purchase of Konami or Square-Enix would be seen as a lot more strategically viable option. I doubt Konami is in a position to be bought out, since their gambling machines provide a solid enough base for revenue, but if Square finds itself sliding any further down, Nintendo would be the most likely of the 3 to have enough funds for an outright takeover (I base this on Sony having junk status credit rating and Microsoft heading into uncertain waters with Windows 8 and the Surface).











