When I first saw this I figured Yamaha wanted access to Line6’s modeling technologies, and not their audio interface capibilities - I love my Variax and PodHD500. This is the bulk of Line6’s product mix. A very common reason for companies to buy other companies is for the patents. Yamaha already possesses the capability to build audio interfaces, they wouldn’t need to buy Line6 to get that (unless there was a potential patent violation Yamaha is trying to avoid which seems unlikely).
This posting on KVR reinforces my opinion.
I also see this this is a good thing. Seems to me Steinberg’s customer responsiveness improved after Yamaha got involved.
As a humorous side note on patents, I just finished taking the Coursera ChucK programming class - which is a language to do music with and I highly recommend for those so inclined. In the language documentation the following boilerplate appears many times
The basic Chowning/Stanford FM patent expired
in 1995, but there exist follow-on patents,
mostly assigned to Yamaha. If you are of the
type who should worry about this (making
money) worry away.