Game is rough for Fiddlesticks. Drain is easily prevented and stopped, Fear is good but the cooldown is too high. His "nuke/"silence is okay, but pretty below average.
Problem with Fiddle is he is insanely outclassed in every area by frequent heroes and hes easily shut down. Ideally to synergize and actually pull off your ultimate you'll want flash and/or Anunu(sp)'s ultimate.
Right now his nuke is way too weak. The damage should be buffed, and/or the bounce reliability should be buffed, and/or the cooldown significantly lowered.
Considering his drain is fairly useless his silence should have a lower cooldown, but keep the damage. This should be relatively spammable since its his only way of dealing damage.
Fear is good, but the cooldown is high and it should last about a second more - especially when you consider Shaco has his jack-n-boxes that can be placed all over and fear.
Simply put hes not even worth playing. You could be really good, but you just won't be able to work with him because while his moves synergize well with eachother they rely on precision and prayer that your enemies have zero disable - which is unlikely.
Right now if you had to play him Banshee's is probably a must eventually, Ninja Tabi or Movement 3 boots, and Rylai or Rod of Age stacking. Instead of going for AP, though, it might be better to go for tank items since really the damage and AP scaling of his silence is laughable and he has no other reliable damage moves aside his ultimate which you may get more bang for your buck with banshees/additional tank items than with stacked AP as you will live out the duration of your ulti. Then again, of course, theres there problem of failing to keep up with end game with lack of AP. May want to consider half/half.