With rather inconvenient timing, information regarding the inner workings of MMC5 PCM sound were posted yesterday, 1 day after the release of Nintendulator 0.700. Support for this feature (though it is not known to be used by any games) has been added.
Additionally, limited support for NES 2.0 format ROM images has finally been added - for now, this consists solely of handling images with more than 4MB of PRG ROM and 2MB or more CHR ROM.