According to a wheel building book I read, the hubs should be placed such that the writing can be properly viewed from the riders perspective.

Of course, it doesn't really matter in the long run, but according to the book this is the accepted, traditional method and should be used whenever someone is building nice wheels. This should be set up so the rim stickers read properly from the drive side of the bike at the same time.l

Can't remember what the title of the book was, but it was pretty decent.