As answered in the iEvo thread... nothing will improve Moonshell.
However there is the DSTwo, and it has it's own homebrew, but it has to run it's own special homebrew to take advantage of the faster speed and such, and even then it's not that much more powerful than the DS.
The DS series is old and weak. Buy a PSP or something else if you want good emulation and video playing.
I will think about it, I don't like PSP games, they are so bored, yes have good graphics but are bored game, so I will use only for emulator.
By the way, can i watch full movies, series and videos with high bitrate and framerate?
Does the quality of PSP videos are really in HD?