No doubt that people still play them but probably very few. If it were me, I wouldn't go with the idea. Too much time and very little amount of people play these anymore.
The browser MMO "game" is still very much a market worth looking in to! More and more people are familiarizing themselves with the internet these days and looking for ways to pass the time at the computer (which that in itself is becoming more common). As with any market (it seems more relevant here), don't pick an idea that's been used over and over again. There are tons of games that share similar concepts (and code, even) which makes for a dry market that's unappealing to both players and developers. Don't shoot to big at first, either. Be realistic with your ideas and goals. Good luck