Thanks for the link. I knew power would not be a pretty issue, but the other one that came to mind was whether you could count on instruction timing. That article confirms that you can't. The WS2811 and other such chips expect pretty tight timing. Simple to do with Arduino, just use the asm macro to directly do a string of NOP and then bit operators directly on the port register you've connected your data line to.
Now if you're doing something that you need a beast like this for, you can hook up an Arduino or two and just use i2c to communicate. (Then again, in many cases a Due would be good enough).