The problem I see with changing the stadium name is do we change it every 3 years or so as currently happens with shirt sponsors?Most of the PL teams have had at least 10 shirt sponsor name changes since season 1982/3. We have had 12. However Reebok and Britannia have been in there for the long haul so far as stadium sponsors.
Newcastle are renaming their ground in the sense that the bloke who owns the club is naming it after his other business.That's the important bit. They've not sold it to anyone else, this puts it in the shop window and garners a bit of free publicity. Established grounds with names which have been around for over a century like St James' Park or Villa Park etc etc will never fetch top dollar for name changes for precisely that reason - everyone will call them what they've always been called.