Except for the obvious intranet related issues, I have two problems with this:
1. That its messy – its like on Windows where once software installed itself anywhich where it wanted, like c:\stuff, c:\more-stuff and you ended up with tons of junk on your c: drive and now everything is tucked aways in neat directories. gTLDs work the same by letting people experience stuff in an orderly fashion.
2. I have a problem with this capability only available for big corporations that can invest the money in taking out parts of the global namespace and reserving it for themselves. Registering a new gTLD would cost something like $100,000 and registrants will not be required to provide “non-sponsored” domain registrations (which means – they will be required to allow registrations of domains under their new gTLD, but they aren’t required to have this done in a non-discriminatory manner. So for example Sony will need to allow registrations under their “sony” gTLD, but they can allow this only for Sony subsidiaries).