I'd say save the $860.00 for a couple of weeks and wait. There is a good chance that the Sandy prices will drop some.
Also I assume you are going to "reuse" many of the parts in your proposed build. If not you are spending too much money for a build that you are only going to use for less than year.
I'll be reusing practically everything in that build aside from the CPU and GPU (Which I will keep as backup)
As mentioned before, all i'll be upgrading this year would be the GPU to a NVidia 600 series once they are all released, an Ivy Bridge i5, might buy an SSD, and maybe the RAM will be switched out for 1600's if I do want to upgrade it.