Hello all, my first post here so go easy on a newbie 
I'm thinking about upgrading my rig to bolster it for the next couple of years and I hoped someone might offer me some advice for what to do. Currently my PC is something of a mish-mash, and I've been doing "bitty" upgrades at irregular times over the last year or so.
* PSU: Enermax 620W Modular
* CPU: Core2 E8500 with Arctic Freezer Pro cooler
* Mobo: Asus P5Q-E
* RAM: 4GB Corsair Dominator DDR2 RAM
* HDD: 2x WD7502AAEX Caviar Black 750GB in RAID 0
* GFX: MSI Cyclone GTX 460 1GB GDDR5
* Display resolution is 1920x1080
* Case: Coolermaster Centurion 5
Everything is running at stock speed. The hard drives were bought a few months ago before the floods, and the graphics card was bought in February to replace an 8800GTS 512MB. Everything else is just over 3 years old, bought from Overclockers.
It's pretty much exclusively used for gaming. In things like Skyrim and Dungeon Defenders I'm starting to see a bit of slowdown - Skyrim is playable enough on High settings but Ultra is much less so (at a guess, < 20fps). DD seems to eat CPU cycles for breakfast when there's lots of action on-screen. And then, looking to the future, I really want a silky-smooth experience for Guild Wars 2 next year. Mmm, where's that crystal ball of mine...
So, I think my 2 questions are:
* Is my CPU bottlenecking gaming performance at this point?
* Would I notice a difference if I (a) upgraded to an i5 2500K, or (b) overclocked my existing kit - I hear it's not too scary to do?
With Ivy Bridge stuff just around the corner I'm not sure whether to wait it out a few more months or not. Either way I've got a budget of about £400 waiting to be thrown on new toys, if its needed. Will happily consider any and all comments!

I'm thinking about upgrading my rig to bolster it for the next couple of years and I hoped someone might offer me some advice for what to do. Currently my PC is something of a mish-mash, and I've been doing "bitty" upgrades at irregular times over the last year or so.
* PSU: Enermax 620W Modular
* CPU: Core2 E8500 with Arctic Freezer Pro cooler
* Mobo: Asus P5Q-E
* RAM: 4GB Corsair Dominator DDR2 RAM
* HDD: 2x WD7502AAEX Caviar Black 750GB in RAID 0
* GFX: MSI Cyclone GTX 460 1GB GDDR5
* Display resolution is 1920x1080
* Case: Coolermaster Centurion 5
Everything is running at stock speed. The hard drives were bought a few months ago before the floods, and the graphics card was bought in February to replace an 8800GTS 512MB. Everything else is just over 3 years old, bought from Overclockers.
It's pretty much exclusively used for gaming. In things like Skyrim and Dungeon Defenders I'm starting to see a bit of slowdown - Skyrim is playable enough on High settings but Ultra is much less so (at a guess, < 20fps). DD seems to eat CPU cycles for breakfast when there's lots of action on-screen. And then, looking to the future, I really want a silky-smooth experience for Guild Wars 2 next year. Mmm, where's that crystal ball of mine...

So, I think my 2 questions are:
* Is my CPU bottlenecking gaming performance at this point?
* Would I notice a difference if I (a) upgraded to an i5 2500K, or (b) overclocked my existing kit - I hear it's not too scary to do?
With Ivy Bridge stuff just around the corner I'm not sure whether to wait it out a few more months or not. Either way I've got a budget of about £400 waiting to be thrown on new toys, if its needed. Will happily consider any and all comments!