Google to Acquire GrandCentral? is a recent rumor. The author adds a tongue-in-cheek comment "I wonder why Google would want that company...". GC is all about owning identity of course, and all Google fans now that Google's core strategy is owning identity management and authentication.
I'd probably rather Amazon owned my identity, but I'll take Google over Microsoft or the Banks.
I like GC, but I'm not willing to commit to them (put my GC number on my business card) until they show evidence of persistence. A Google acquisition would do that.
Using a GC number on your business card would eliminate the biggest downside of using a corporate mobile account ...