One of the other things that will be coming with 2.1 is much more memory efficiency. On things like the due and teensy 3/3.1, this isn’t that big of a deal, but on the uno, with only 2k of ram, and even more importantly, on the trinket, with 512 bytes of ram, memory is a bit tighter.
I’ve now got one of the demo/calibration/color torture tests that mark and I use running on a trinket, with 110-120 leds. (E.g. 64-70% of memory available for use for led data. The rest is taken up by the stack, a lookup table that is used for sin16, and some global data pointers).
Follow up - 32 bytes of the 152-162 bytes of ram remaining is used by a lookup table used by sin16.
I think I want to track down where the rest of the 120-130 bytes are being used up. AVR does a lot of stack pushing, and so I suspect that some of that ram is used by a stack full of stored registers. I should see if there’s any ways to trim that down further.
And actually, i think I have a way to drive nearly 700 LEDs off of a trinket. I’ll let you folks do that math on 700 LEDs with 512 bytes of ram, total 
Whoah. This would be awesome. The problem I ran into on the Yun was that after 1728 bytes of “framebuffer” for my 576 pixels, there wasn’t enough RAM left for the Bridge library, so I couldn’t read from the SD card.
I abandoned that line of inquiry for my “deadline” the other week, but I’ll get back to poking at it next weekend maybe.