The Core i5 3570K will outperform the A10-5800K in every single situation you can think of EXCEPT for integrated graphics performance. They're really not comparable at all considering they are $70 apart in price. The Core i3 3220 is what you should be comparing to the A10-5800K. The FX-8350 is what you should be comparing to the Core i5 3570K.
One thing I will tell you is socket FM2 is supposed to get a solid 3 years of processor support (AMD said this themselves) however LGA 1155 is in the process of being phased out by LGA 1150 in a matter of 3-4 months. BUT the A10 is the best you can get with socket FM2. There's no CPU with the equivalent power of a Core i5 on socket FM2, nor are there any plans for there to be...currently at least.
Video on Haswell and LGA 1150.Edited by M3T4LM4N222 - 2/7/13 at 7:49pm