Does this mean graphics card will be obsolete in the future ?
"APU" = Accerated Processing Unit. It is a term AMD came up with for a CPU that also has a graphics integrated inside it. Intel's Core i3/i5/i7, Pentiums, Celerons, and Atoms all have integrated graphics cores (the are a few exceptions), but Intel still refers to them as CPUs.
Add-on or discrete graphic cards will always exist. Integrated graphics (iGPU) more or less sucks compared to discrete GPUs. The Radeon HD 8670D is the best iGPU in AMD's APUs for the desktop. However, it is only as powerful as a Radeon HD 6670 DDR3 discrete graphics card. The Radeon HD 6670 comes in two flavors, DDR3 and DDR5. The DDR3 version has about 76% the performance of the DDR5 version. This places the HD 8670D between a Radeon HD 5570 and Radeon HD 5670 which are graphic cards from 2 generations ago.