I happen to have a different take on the entire statement, I might be completely off the mark here.
(In computing) Service Oriented Architecture is the trend as of now. But what is trendy in 2014 can become ______ in 2015
The first part of the statement, (In computing) Service Oriented Architecture is the trend as of now.
it gives me the idea that SOA is becoming mainstream at present. As a developer, something that is a trend presently is something that is an accepted entity and is widely accepted. It also points to something being quite mainstream.
With this context, may I propose,
(In computing) Service Oriented Architecture is the trend as of now. But what is trending in 2014 can get challenged in 2015
While trying to keep the negative in check, there has to be a reduction of stress in the second part of the sentence (referring to 2015).
Another way I interpret this is that SOA is fairly new, and with it's user base increasing rapidly, applications increasingly migrating to it etc. Hence, the excitement about it needs to be captured. How about something on the lines of:
(In computing) Service Oriented Architecture has shown huge promise. But what is trending in 2014 can become quite mainstream in 2015