We have realized silicon-on-insulator photonic crystal (PhC) waveguides with intense 1.54 um emission at room temperature. The slabs contain a thin layer of SiO2 with Er3+ doped silicon nanoclusters embedded at the center of the Si core and are patterned with a triangular lattice of holes. An enhancement by more than two orders of magnitude of the Er3+ near-normal emission is observed when the transition is in resonance with an appropriate mode of the PhC slab. The results are in very good agreement with calculated photonic bands and emission spectra. These findings are important for the realization of Si-compatible efficient light emitters at telecom wavelengths.