iPhoto has shortcomings but the library/database is the same as Aperture and I believe Apple is delaying Photos because they DON'T want another FCP X. While I didn't like the Logic X upgrade it ruffled a LOT fewer feathers and I think is a sign that Apple is being a bit more careful about alienating pros while it goes after the lucrative prosumer market.

I moved to LR two years ago (when it was apparent that Aperture was abandonware) with north of 350gb of raw images (at that time). I now have hundreds of gb more and there is no way I am doing anything but using LR and PS...
My story is not unique and frankly

As an aside, it doesn't matter if Photos is an absolute killer app, there is no going back...