I'm no engine guru, but it seems to me that while such a thing might be necessary for certain applications where space is really at a premium, it would be better to have a single inlet than to have the turbulence caused by the second pipe.
Not to mention the teeny tiny little filters. I like foam, but if you're going to use it, it has to be bigger to make up for it's poorer (per square inch) flow characteristics (over oiled gauze).
