We explored the effect of intertube interaction in bundles of single-wall CNTs and multiwall CNTs. Because of small intertube interaction and lattice frustration, we predicted very soft libration modes to occur and to disappear above the orientational melting temperature which marks the onset of free tube rotations about their axis. We also predicted such weak intertube coupling causes an additional electronic band dispersion of < 0.2 eV and opens up a pseudogap of the same magnitude at the Fermi level in the rope of (10,10) SWCNTs. In a (5,5)@(10,10) double wall CNT, the weak interwall interaction and the symmetry reduction causes four pseudogaps to open and close periodically near the Fermi level during the soft librational motaion. This electron-libration coupling, absent in solids composed of fullerenes and SWCNTs, may yield superconductivity in MWCNTs.