Color me disappointed. The blog makes some nebulous claim about Cue retaining Greplin's features, but makes no specific assertations about the future of search. If you're retaining those features, why have you made them inaccessible? The Greplin website redirects to Cue, so I can't search now. If search is indeed gone, so be it, but I can't help but wonder why you've cut me off from your service before the new UI is ready for me to use.
Search is still there and still a huge part of the product. I think they've come to the realization that the future of personal search is in making it so you don't have to use search in the first place -- 9 times out of ten the information will already be there in front of you when you open the app.
You might want to perform a search a few times a month, but you'll want to use the new "What's next" view a few times a day.