Is this really such a big job? It's not as if wifi on aircraft is that cutting edge any more - other airlines have had it for some time.
If this all trundles along like the CW catering and bedding roll out it could clearly take a little time (translate as 'if you a LGW traveller don't hold your breath).
On the 787s, if they are going to be sat around awaiting engines then surely a good opportunity to handle it.