11:47 AM
@FrankScience: there is a fiber sequence of A-bimodules: L_A-->U(A)-->A, where L_A is the E_1-cotangent complex and U(A) is the enveloping algebra A \otimes A^{op}. Tensoring over U(A) with A gives HH(A) as approximately a shift of L_A\otimes_{U(A)}A.
Also: there is no issue about simplicial/vs spectral for E_1-algebras.
(that's only for E_infty stuff)
Also, for noncommutative things, it's not true that the stabilization/abelianization of algebras augmented over A is A-modules, it's A-bimodules. (Hence the appearence of U(A) above). Notice that the derived functor of derivations involves deriving bimodule maps out of the cotangent complex, in Quillen's setup
that's why you see a tensor product over U(A) when you're doing homology vs. cohomology.
Finally, @DenisNardin, (topological) Hochschild cohomology does have to do with deformations: THC^{(n)}(A)[n], the E_n Hochschild cohomology shifted by n, turns out to have a spectral Lie algebra structure that controls deformations of the category of E_n-A-modules. (This is the point of view of John Francis's thesis, you can read about it there.) Specifically, this shifted THC is the tangent complex to an E_n-moduli problem.
In the E_1-case this is classical, that hochschild cohomology tells you about deforming the category of bimodules.