I wouldn't be as quick to bash them. My guess is their projections indicate there is still demand for their line up, but supplies and materials for the old models were running thin, and they decided to update the look and feel while possibly increasing their margins in the long run. It's business. I don't see that downfall to mediocrity many of the users seem to note. Their product is still competitive, although maybe with too familiar a face. I wouldn't be surprised if they introduced new top tier product soon, also.
I don't think it's just based on this. The ADV was a pretty big disappointment for almost everyone who tried it on here that I can remember. Combine the ADV + the 'new' UM and W series and yeah, people are disappointed. I'm sure everyone will forget about it if Westone just releases a new IEM that improves on the W4 or UM3X.