I'm at 9 currently, but if I use a weekend I'll go to 20, and if I get another week I'll go to 40 with cleaning up. I'm just too lazy. So to answer your question, probably 9 (10 if I feel to do the last 2 trophies in GOW: A. 
).
If I get even one plat when I have my PS4 that will be an achievement since I'm too busy to bother with the stuff, and I find they're usually not fun at all (Ninja Gaiden Sigma 2). I got the platinum trophies in Skyrim and Heavy Rain naturally without even trying since they were fun and interesting (respectively).The other stuff were just a yawn, so I'll just play the games in my backlog till I beat them on the hardest difficulty setting or till I'm bored of them.
Playstation = The Beast from the East
Sony + Nintendo = WIN! PS3 + PSV + PS4 + Wii U + 3DS
