I played it a lot when it first launched, and landed at level 15. Haven't picked it up in about 5 days though, it really doesn't have much substance.
I've been playing it when I can...the servers have been absolutely abysmal. I'm level 7 right now but all my Pokémon only have CP in the 100-200s, so I can't really take on any gyms or anything. Getting really sick of finding Pidgey and Rattata too. It's a fun time waster but it's going to get old fast unless they're quick with adding new gens and features.
I'm enjoying it. It has infected my workplace, and it is very much a social game. We have a Pokémon chat channel in the office now. In which I'm exploring writing a chatbot to alert us when a Pokémon is in our vicinity or the servers are down. We'll go for a walk at lunch or after work to look for Pokémon. I'm leaving my screen on during my walk from the train to the office in the morning. I have a portable backup charger with me because this thing sucks battery juice like nobody's business. For whatever reason, Drowzees seem to be the common critter in my area. I would like to see some more variety. I'd also like to be able to battle soon, but to get to that is way too much work. So, I'm just going to focus on collecting. It's fun, for now. Will it be relevant six months from now if nothing changes it? Probably not.
Anyone still playing? It seems like most people I know played for maybe a month and then it just died. Which isn't a surprise...it's a pretty shallow experience and Niantic isn't pushing out updates to keep interest - and the updates they pushed out in the first few weeks of the game did the exact opposite and killed most people's interest. It just seems mishandled from day one.
I still play it. In that I leave it on while walking around normally. And glance occasionally to see if something cool is near by (often, there is not) I don't go on purposeful Poké excursions anymore though, because it is October - it is dark and cold. But I'll return it one day, I'm sure.