Read this as "Google Now" the product, please lowercase the now at least.
So just because a company uses an ambiguous term as a product name ("Now"), that's the final nail in the coffin of title case? Seems a bit silly to me...
There's nothing ambiguous about the product name. Title case is the source of the ambiguity (and its not specific to particular product names, it happens anywhere where a title is an English sentence in which obliteration of the normal capitalization distinctions creates ambiguity.)
And that's the problem with title case -- it obstructs, rather than facilitates, clear communication.