AMD's APU's have proven to be very much superior GPU wise to Intels integrated GPU's, but still if you're looking for a gaming machine nothing can really touch discrete hardware when gaming at 1080p and above. At lower resolutions you might be able to get away with an APU depending on the game.
I would personally get the i5 3470, maybe overclock it a bit and pair it with a decent GPU.
CPU wise performance is still in Intels court, so if the tasks you do require fairly beefy cores, then the i5 3470 would be the better pick in that arena as well.
well, im getting a msi hd 7870, heard the amd trinity can use like 2 graphics card , apu and other graphics card and would perform better. It better price than the i5 and better clock speed. But now there isn't many am2 mobos so probably have to wait awhile.
Yes you can it's called hybrid crossfire but you won't be able to crossfire with that video card. With the APU's you can only crossfire with lower end graphics card, I think the limit is a 7670. If you put the 7870 in there it will turn off hybrid crossfire and will be be just a single dedicated graphics card. So you'll have a low end CPU with a higher end video card wich could cause lag problems. Personally if you can afford the I5 I would go for it. AMD really has nothing that can compete with Intel's I5 and I7's in sheer CPU performance power.