Quasielastic neutron scattering combined with deuteration labeling has allowed us to follow selectively the dynamics of the hydrogens of poly(ethylene oxide) (PEO, T-g approximate to 220 K) in a blend with poly(vinyl T-g(blend) = 280 K) Temperatures between T-g(blend) acetate) (PVAc, T-g = 315 K) (20% PEO/80% PVAc in weight, T-g(blend) = 280 K. -10 K and T-g(blend) + 120 K have been explored by backscattering techniques, accessing a dynamical window centered on the nanosecond range and with momentum transfers Q in the inter- and intrachain region. Two essentially different dynamical behaviors have been identified for PEO in the blend: (i) at high temperatures (approximate to lend + 100 K) the dynamics is not qualitatively different from that of a glass-forming homopolymer (regarding spectral shape and dispersion of the time scales); (ii) close to T-g(blend), extremely broad distributions of relaxation times are found that do not depend on Q in the high-Q range, strongly suggesting localized dynamics. Apparently, lend the slowing down of the motions in the PVAc component toward T-g(blend) leads to the confinement of PEO dynamics on small length scales. As soon as the dynamics of the more rigid polymer becomes fast enough to allow PEO long-range relaxations (approximate to T-g + 80 K), the fast component reaches a situation of certain equilibrium, at least for length scales of the order of a nanometer. Our results perfectly agree with those reported for PEO in a blend with poly(methyl methacrylate) [Genix et al. Phys. Rev. E 2005, 72, 031808]. The confined processes in both "rigid environments" show nearly identical features. In addition, neutron diffraction experiments with polarization analysis indicate that, while blending hardly affects the short-range order of PVAc chains, it leads to larger and more distributed characteristic distances involving PEO segments.