FYI: The statement should be the honeymoon phase, derived from the nothing-but-bliss albeit short-lived marital phase, rather than the lunar one.
P-GO is likely to reach its peak in a few days... If some exciting content updates don't follow they may have a problem keeping people around. They'll definitely retain many fans (people still play the original handheld versions), but it will be interesting to see what happens in the future. Also, from own experience - it was easy to play Ingress and go on long walks initially. But after a while, you really want to spend time doing other things; past some point a 1h trip to do something specific for virtual points loses the appeal.
Pokemon Go has all the right elements at exactly the right time. It's going to be tremendous if they can keep up.
I haven't played Pokemon Go, but if you can't do this, what exactly are people doing in the game? Just collecting Pokemon and doing nothing with them? Honest question -- I had implicitly assumed being able to battle with collected Pokemon was the whole point.
Now, the adult mobile gaming market is saturated.
There isn't very much flexibility that the game offers, and even it if will offer it in the future, the initial moon phase will be over by then.
It's a nice example of launching a product and getting people to use it, but within a few weeks Pokemon Go will be history, unless of course, people find more dead bodies or other surreal stuff while playing the game, though I wonder if that's the reputation that the developers are going for.